2-beta-alkenyl penam sulfones as beta-lactamase inhibitors

RAN 4410/238 The present invention relates to penam derivatives, in particular it is concerned with 2p-alkenyl-penam derivatives of the general formula wherein one of R1 and R2 signifies -COR4, -CN, -CH2R5, halogen, -CH=CHR6 or Q and the other signifies hydrogen or lower alkyl or both together signify a y-lactam ring, R3 signifies hydrogen, lower alkyl, aryl-alkyl, allyl or a residue which is cleavable in vivo, R4 signifies hydrogen, lower alkyl, lower alkoxy, benzyloxy, amino, lower alkylamino or lower alkyl-lower alkoxyamino, R5 signifies hydroxy, -OCONHR7, -OCONH2 or a five- or six- membered hetero-aromatie ring which contains N,S and/or O and which is linked via a nitrogen atom, R6 signifies -CN or CHO, R7 signifies -COCH2GI, Q signifies a five- or six-membered hetero-aromatie ring which contains N, S and/or O and n signifies 0, 1 or 2, as well as pharmaceutically compatible salts of these compounds. These compounds are novel and are distinguished by thera- 3 0 peutically valuable properties. In particular, they have pronoun¬ ced -lactamase inhibiting properties and are accordingly useful in combination with -lactam antibiotics such as the penicillins and cephalosporins in the control of pathogens which form p- lactamase. Pop/So 17.6.S4 Furthermore, they have an antibacterial activity of their own against certain bacterial strains, such as e.g. Acinetobacter spp. The term "lower alkyl", alone or in combination such as "lower alkoxy" or "lower alkylamino", signifies straight-chain or branched saturated hydrocarbon residues with a maximum of 7, preferably a maximum of 4, carbon atoms such as methyl, ethyl, isopropyl or t-butyl. The term "aryl-alkyl" embraces benzyl, benzhydryl, p- methoxybenzyl or p-nitrobenzyl. The term "halogen" embraces fluorine, chlorine, bromine or is iodine. The term "five- or six-membered hetero-aromatic ring which contains N, S and/or O" preferably signifies 2-pyridyl, 1- methyl-pyridin-2-ylio, 1,3-thiazol-2-yf, 1,2,4-oxadiazol-3-yl and the like. A residue which is cleavable in vivo signifies a residue which is suitable for oral administration and which preferably contains an ester group such as, for example, -CH200CC(CH3)3, Me Cri? CmCH&XKO-Q t CHCCHOCO-jOMe ' ? or -CH(CH3)OCO-CH3. 3 0 Objects of the present invention are 2j*-alkenyl-penam derivatives of general formula \ and pharmaceutrcally compatible salts thereof per se and as pharmaceutically active substances, the manufacture of these compounds, medicaments containing a compound of general formula r or a pharmaceutically compatible salt and, if desired, additionally a (Mactarn antibiotic and the manufacture of such medicaments, as well as the use of com- • • f • « t I « pounds of general formula I and of pharmaceutically compatible salts thereof in the control or prevention of illnesses, especially of bacterial infections, and, respectively, for the manufacture of corresponding medicaments. Furthermore, compounds of the general formula COOR3 i o wherein R3 has the above significance, are an object of the invention. These compounds of formula II are important intermediates for the manufacture of the compounds of general formula I. Those compounds of general formula I in which R1 = CN, halogen or COR4 and R4 - amino, methyl, lower alkoxy or benzyl- oxy and R2 - hydrogen, e.g. the following compounds, are espec¬ ially preferred: Benzhydryl (E/Z)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl- 7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate, benzhydryl (E)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate, benzhydryl (Z)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate sodium CE)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl-4,4,7- trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate sodium (ZMaS.SS.SRJ-S--cyanoethenyO-S-methyMJ- trioxo-4-thia-1-aza-bicyelot3.2.0]heptane-2-carboxylate, sodium (Z)-(2S,3S,5R)-3-(2-chloro-vinyl)-3-methyl-4,4,7* trtoxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate, sodium(E}-(2S,3S,5R)-3-methyl-3-(3-oxo-but-1-enyl). 4,4,7-trioxo-4-thia-1-a2a-bicyclo[3.2.0]heptane-2-carboxylate. Furthermore, the following belong to the especially preferred compounds: Benzhydryl (E/Z)-(2S,3Sf5R)-3-(2-carbamoyl-vinyl)-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate, benzhydryl (E)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3- methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate, benzhydryl (Z)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3- i o methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2- carboxylate, sodium (E)-(2SI3S,5R)-3-(2-carbamoyl-vinyl)-3-methyl- 4J4)7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate, sodium (Z)-(2SJ3S,5R)-3-(2-carbamoyl-vinyl)-3-methyl- 1 5 4J4)7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate) benzhydryl (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3- methyl-oxo-thia-l-aza-bicyclotS.OJheptane-carboxylate, benzhydryl (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3- methylJ-trioxo-thia-l-aza-bicycloIS.CJheptane- carboxylate, sodium (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3- methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate, benzhydryl (E)-(2S,3S,5R)-3-(2-benzyloxycarbonyl-vinyl)- 2 5 3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxy- late, benzhydryl (E)-(2SI3S,5R)-3-(2-benzyloxycarbonyl-vinyl)- 3-methyl-4,4,7-trioxd-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate, sodium (E)-(2S(3S(5R)-3-(2-benzyloxycarbonyl-vinyl)-3- methylJ-trioxo-thia-l-aza-bicyclofS.Ojheptane-car- boxylate. The 2p-alkenyl-penam derivatives of general formula I as 3 5 well as their pharmaceutically compatible salts can be manu¬ factured in accordance with the invention by a) reacting a compound of the general formula jDC n cr COOR3 wherein R3 has the significance given above, with a compound of the general formula R8 R2 wherein R1 and R2 have the significance given above and R8 = P®(aryl)3, PO(Oalkyl)2I Si(alkyl)3 or halogen, in the presence of an activating agent, or b) oxidizing a compound of general formula I in which n signifies 0, or c) converting a compound of general formula I in which R3 is different from hydrogen into the corresponding free acid, and d) if desired, converting an acidic compound of formula I fnto a pharmaceutically acceptable salt. Scheme 1 shows two known methods (Wittig or Horner reaction) for carrying out process variant a). Scheme 1 £Oc°-~ pfr* R1 COOR3 COOR3 _.R n y-<2 HI R la The substituents R1, R2 and R3 have the above significances. I t • • The aldehyde of formula II is converted into the alkenyl- substituted penams of formula la by direct reaction with an alkylidene-triphenylphosphorane (III; Y « P®(aryl)3, Wittig reaction) or with an alkylphosphonate (III, Y = (alkylOJaPO, Horner reaction) in the presence of an activating agent, for example a base such as triethylamine, sodium methylate, lithium di- isopropylamine or DBU (1,5-diaza-bicyclo[4.3.Q]non-5-ene). Suitable solvents are e.g. tetrahydrofuran, toluene, dichloro- methane, acetonitrile or benzene. The reaction temperature can 1 o vary between -30° and 80oC depending on the solvent which is used. If desired, the compounds of formula I can also be manu¬ factured by reacting correspondingly substituted triphenylphos- phonium halides with 1,2-butylene oxide as the base and solvent. In this case the preferred reaction temperature lies between and 70oC. Compounds of formula I in which n signifies 0 are obtained. 2 0 The Peterson olefination and the Reformatsky synthesis are further possibilities for carrying out process variant a). In the i'.... case of the Peterson olefination, lithium derivatives of trialkyl- silanes are reacted with compounds of formula II in the presence ##.:.. of a base. Scheme 2 shows the reaction with a lithium trimethyl- 2 5 siiane of formula IV in which R1 and R3 have the significances given above. il • • * a Scheme 2 /JVC COOR3 n (CHjSi-CH-Li I R1 IV RJ S .CH-CH-SitCH OH COOR3 V jCo COOR3 lb The 2p-alkenyl-penam derivatives of formula lb result from the compounds of formula V by spontaneous dehydration. Com¬ pounds of formula I in which n signifies 0 and R2 signifies hydro¬ gen are obtained. In the case of the Reformatsky synthesis, compounds of formula II are condensed with organo-zinc deriva¬ tives of a-halo esters to the corresponding -hydroxy! esters of formula VI, from which compounds of formula I in which n signi¬ fies 0, R1 signifies COR4, R4 signifies lower alkyl and R2 signi¬ fies hydrogen result by water cleavage, corresponding to Schem# 3. Scheme 3 f0co Zn BrCHa-CQOAIk COOR3 .3 « S sCH<HrCOOAi:k OH n COOR3 VI tOC COOAlk COOR3 Ic R3 has the significance given above. .•.•*•. 3 0 The oxidation of the sulphide group to the sulphoxide group or sulphone group is effected according to methods known per se. Reaction of the compounds of general formula I in which n signi- fies 0 in a two-phase system with ruthenium tetroxide or with an aqueous potassium permanganate solution and with a hydrogen peroxide solution has been found to be especially suitable. Other oxidation reagents such as Na2W04 or peracids can i o also be used for the preparation of the penam sulphones. Di- chloromethane is an especially suitable solvent. The compound of general formula I in which n signifies 0 is conveniently dissolved in dichloromethane and added to an aqueous suspension consisting of sodium (meta)periodate, sodium bicarbonate and ruthenium(JV) oxide. After completion of the reaction the organic phase is separated, purified and dried. Whether a sulphoxide or a sulphone results from this 2 0 oxidation depends on the nature and/or amount of oxidation agent. The conversion of a compound of formula I in which R3 is different from hydrogen into a free acid and the conversion of a free acid into a pharmaceutically acceptable salt can be effected 2 5 according to methods known per se, in certain circumstances in a single procedure. Ester groups, e.g. benzyl, p-nitrobenzyl, benzhydryl, p- methoxybenzyl or allyl, can be cleaved off as follows: Benzyl and p-nitrobenzyl by hydrogenation over palladium- carbon at about 0oC to 80oC in an organic solvent such as ethyl acetate, methanof or water or by hydrolysis in the presence of sodium sulphide at about 0oG to room temperature in a solvent 3 5 such as e.g. DMF. Allyl by palladium-(0)-cataIyzed transallylation in the presence of a sodium or potassium salt of 2-ethylCaproic acid, benzhydryl with m-cresol at about 50oC within 4-5 hours. I < The compounds of general formula II which are used as starting materials can be prepared from corresponding alcohols in analogy to the process described in Tetrahedron 42, No. 5, pp 1003-1012. Scheme 4 fXJK dmso, (coa)2, CH2a2 JIiO\ COOR 1>im3 COOR3 vin n i o In this, R3 has the significance given above. Reaction with oxalyl chloride in dichloromethane has een found to be of advantage, with the following procedure conven¬ iently being used: dichloromethane and the oxidation agent are cooled to about -60oC, treated with DMSO and a compound of formula VIII and, after a reaction period of about 3 hours and addition of triethylamine, the cooling bath is removed. The thus- obtained aldehyde of formula II can be purified using usual methods. Compounds of general formula II are obtained analogously by oxidation with PCC (pyridine chlorochromate), Dess-Martin reagent, MnOg and the like. As mentioned earlier, the compounds of general formula I in accordance with the invention and pharmaceutically compatible salts thereof with bases exhibit pronounced p-lactamase-inhibit- ing activities against -lactamases from various bacterial strains. As illustrated hereinafter, these therapeutically 3 0 valuable properties can be determined in vitro on isolated p- lactamases: I' A. Isolation of the B-lactamaspg Various p-lactamases can be isolated from penicillin- or cephalosporin-resistant bacterial strains such as Klebsiella pneumoniae NCTC 418, Proteus vulgaris 1028, Bacillus licheni- formis 749/C, Escherichia coli SN01 and Citrobacter freundii 1203. For this purpose, the corresponding strains are cultivated in tryptic Soy Broth (Difco) and harvested by centrifugation in ihe last logarithmic growth phase (when necessary 50-100 mg/l i o of ampicillin are added to the medium towards the end of the log- phase in order to induce the p-lactamase). The thus-obtained bacterial mass is treated with 20 mM Tris-HCI buffer (pH 7.0); the cells are broken open with a French press while cooling. The mixture is centrifuged (20,000 r/min.) for 20-30 minutes and a clear crude extract is obtained. The purification of the proteins is effected according to the methods Of Cartwright, SJ. & Waley, S.G. [Biochem. J. 221, 505-512 (1980)] and, for B. licheniformis, Ellerby, L.M. et al. [Biochemistry 2£., 5797-5806 (1990)J. 2 0 B. Determination of the B-lactamase activity The determination of the activity of the isolated -lacta¬ mases can be carried out according to the method of O'-Callaghan, C.H. et al. [Antimicr. Ag. Chemother. 1, 283-288 (1972)] using the requisite test batch contains per ml of water: 50 mM phosphate buffer (pH 7.0), 0.1 mM iiitrocefin and sufficient enzyme (-lac¬ tamase) to achieve a AA/min. of about 0.1. The cleavage of the substrate, which is accompanied by a change in colour, is 3 0 effected at 370C and is followed quantitatively at 482 nm using a spectral photometer. C Determination of the B-laetamafte-inhibiting activity of the compounds of general formula I The above-described cleavage of the chromogenic Substrate by -lactamases (test B.) can bs inhibited by the addition of com¬ pounds of general formula I (inhibitors). Since it has been found k • • v m . 11 . that the inhibitors irreversibly inactivate the p-lactamase in a time-dependent reaction, the reaction (cleavage of the substrate) is in each case started by addition of the substrate after a pre¬ incubation period of p-lactamase with inhibitor of 15 minutes. s As a measurement for the affinity of the particular tested inhibitor to the p-lactamase, which is a measurement of the strength of the inhibitor, there serves that concentration which inhibits by 50% (IC 50 in nM) the cleavage of the substrate (nitrocefin) effected under the above test conditions (test B) in the absence of an inhibitor. 4 to 6 tests with different concen¬ trations of inhibitor were carried out in ordep to determine the IC 50. The determination of the IC 50 was effected by means of a graph. 1 5 The results obtained in the above test (test C) are presented in Tables 1 to 3 hereinafter. Table 1 The IC 50 value, given in nM, is a measurement of the p- lactamase inhibition. An IC 50 value of 5 jxM or less is con- sidered to be significant. B-Lactamase inhibitinn aotivity of nnmpnnnds of formula I Examples ofcompound of formula1 with reference IC50C. freundii 1982 ICsotuM]E. coli CF 102 Tazobactam (reference) 0.900 0.015 6c (cis amide) 4.340 0.130 6c (trans amide) 2.250 0.054 5c (trans nitrile) 0.696 0.681 5c (cis nitrile) 0.210 0.126 2c (trans ethyl ester) 0.370 0.456 4c (trans benzyl ester) 0.478 0.444 8c (cis-chloro) 0.590 0.055 9c (trans COCH3) 0.147 0.417 11c (trans 1,2,4-oxadJa-zol-3-yl) 0.490 0.217 12c (trans 2-thiazolyl) 0.410 0.054 12c (cis 2-thiazolyl) 1.270 0.160 13c (trans 2-pyridinyl) 1.010 0.092 14c (trans-CONMe(OMe)) 2.490 0.181 (trans 2-pyridinylio) 3.100 0.087 17b (trans CH-CH-CN(ZM 3.300 0.420 18c (gamma-lactam) 14.250 0.320 20c (trans CH2OH) 6.92 0.590 22c (trans CH2OCONH2) 0.479 0.763 23c (trans CH2-pyridinium) 15.700 0.142 Tgfrlg 2 B-Lactamase inhibiting activitv bv combination of compounds offormula I wih ceftriaxone(1 part ceftriaxone + 4 parts inhibitor) Examples ofcompounds offormula 1 withreference IC frig/ml]C. freundii 1982 IC [ng/ml]E. coll CF 102 Ceftriaxone 128 8 Ceftriaxone +Tazobactam (reference) 8 0.25 Ceftriaxone +6c (cisamide) 4 0.12 Ceftriaxone + 6c (transamide) NA 0.12 Ceftriaxone + 5c (transnitrile) 2 0.25 • •• Ceftriaxone + 5c (cisnitrile) 1 0.25 • ••«• ••• • •••• • Ceftriaxone + 2c (transethyl ester) 4 0,25 • • •••••• »• ••• Ceftriaxone + 4c (transbenzyl ester) 16 2.00 • • Ceftriaxone + 8c (cischloro) 4 0.25 •••••• »••• •••• • * Ceftriaxone + 9c (transCOCH3) 1 0.25 f *• •« Ceftriaxone + 11c (trans1,2,4-oxadiazol-3-vl) 4 0.5 • ••• •>*•• « Ceftriaxone + 12c (trans2-thiazolyl) 8 1 * ••• • •• *• Ceftriaxone + 12c (cis2-thiazolyl) 16 0.5 •••••••• • Ceftriaxone + 13c (trans2-pyridinyl) 8 1 Ceftriaxone + 14c (transCONMe(OMe)) 8 0.5 Ceftriaxone +15 (trans2-pyridinylio) 4 0.25 Ceftriaxone ♦ 17b (trans.CH-CH»CN(Z)) 8 0.5 ft* ft* • ft'**.* «'ftft<« Ceftriaxone + 18c (gamma-lactam) Ceftriaxone + 20c (trans-CHaOH) Ceftriaxone + 22c (trans CH2OCONH2) Ceftriaxone + 23c (trans CH2-pyridmium) 0.5 0.25 MIC signifies minimum inhibitory concentration. • t • t *•« « ft t« In Vitro activity Of combinations of the penam sulphnna derivative 5C With selected antibiotins against Hactafflase over-producftr strains (constant innhibitor concentration: 4 mg/l) MICE. cloacae MICC.freundii MICPs.aeru¬ginosa MICE.coli Ceftriaxone >64 64 >64 I 16 Ceftriaxone + 5c (cisnitrile) 4 2 16 <0.12 Ceftriaxone + tazobacfam 64 32 >64 <0.12 Ceftazidime >64 >64 32 32.00 Ceftazidime + 5c (cisnitrile) 4 8 2 0.5 Ceftazidime + tazobactam 64 64 8 0.5 Piperacillin >128 >128 >64 >64 Piperacillin + 5c(cis nitrile) 8 8 16 4 Piperacillin + tazobactam 128 64 64 4 Apalcillin >128 >128 64 :>64 Apalcillin + 5c (cis nitrile) 16 8 4 2 Apalcillin + tazobactam >128 64 NA 2 **t* l» • * t •;•• k « The products in accordance with the invention can be used as medicaments, e.g. in the form of pharmaceutical preparations which contain them or their salts in admixture with a pharma¬ ceutical, organic or indrganic inert carrier material which is suitable for parenteral or enteral administration, such as e.g. water, gelatine, gum arabic, lactose, starch, magnesium stearate, talc, vegetable oils, polyalkylene glycols, Vaseline, etc. The pharmaceutical preparations can be present in solid form, e.g. as tablets, drag6es, suppositories, capsules; or in liquid form, e.g. as Solutions, suspensions or emulsions. They may be sterilized and/ or may contain adjuvants such as preserving, stabilizing, wetting ©r emulsifying agentsr salts for varying the osmotic pressure, anaesthetics or buffers. The compounds of formula I and their salts preferably come into consideration for parenteral admini¬ stration and. for this purpose, are preferably prepared as lyophilizates or dry powders for dilution with usual agents such as water or isotonic saline. As mentioned earlier, the compounds of general formula I and their pharmaceutically compatible salts can be used in accordance with the invention in the control or prevention of illnesses, especially in the control of p-lactamase-forming to pathogens in combination with p-lactam antibiotics, i.e. anti¬ biotics which contain a p-lactam ring, for example penicillins such as piperacillin, mezlocillin, azlocillin, apalcillin, benzyl- penicillin, phenoxymethylpenicillin, carbenicillin, methicillin, propicillin, tricarcillin, ampicillin, amoxycillin or mecillinam and cephalosporins such as ceftriaxone, ceftazidime, cefetamet, cefatamet pivoxil, cefotaxime, cefmenoxime, ceftizoxime, cefuroxime, cephaloridine, cephalotin, cefazolin, cephalexin, cefoxitin, cephacetrile, cefamandole, cephapirin, cephradine, cephaloglycine, cefpirome or cefepime as well as penems and 2 o carbapenems such as imipenem or meropenem. Thereby, the compounds of general formula I or pharmaceuticaHy compatible salts thereof with bases can be administered before, simultane¬ ously with or after the administration or intake of p-lactam antibiotics. Where the products in accordance with the invention 2 5 are administered simultaneously with a p-lactam antibiotic, then this can be effected by administration as an ad-hoc combination or in the form of a pharmaceutical combination which contains a compound of general formula I or a pharmaceutically compatible salt thereof with a base and a p-lactam antibiotic; such pharma- 3 0 ceutical combinations are also an object of the present invention. The dosage of the compounds of general formula I and of the pharmaceutically compatible salts thereof with bases can vary within wide limits and will, of course, be fitted in each particular case to the individual requirements and to the p* tactamase-producing pathogen to be controlled. In general, a daily dosage of about 0.1 to about 2.0 g should be appropriate. The ratio of p-lactamase inhibitor (compound of formula I or 9 • • pharmaceutically compatible salt thereof with a base) to p- lactam antibiotic can also vary within wide limits and will be fitted to the individual requirements in each particular case. In general, a ratio of about 1:20 to about 1:1 should be appropriate. As mentioned earlier, medicaments containing a compound of general formula I or a pharmaceutically compatible salt there¬ of are also an object of the present invention, as is a process for the manufacture of such medicaments which comprises bringing i o one or more compounds of general formula I or pharmaceutically compatible salts thereof and, if desired, one or more other thera¬ peutically valuable substances into a galenical administration form; in this connection reference is again made to the pharma¬ ceutical combinations referred to above, which are also an object 1 5 of the present invention. In particular, pharmaceutical combin¬ ations containing a compound of general formula I or a pharma¬ ceutically compatible salt thereof and a p-lactam antibiotic, e.g. a penicillin such as piperacillin, mezlocillin, azlocillin, apalcillin, benzylpenicillin, phenoxymethylpenicillin, carbenicillin, methicillin, propicillin, tricarcillin, ampicillin, amoxycillin or mecilliham, a cephalosporin such as ceftriaxone, ceftazidime, cefetamet, cefatamet pivoxil, cefotaxime, cefmen- oxime, ceftizoxime, cefuroxime, cephaloridine, cephalotin, cefazolin, cephalexin, cefoxitin, cephacetrile, cefamandole, 2 5 cephapirm, cephradine, cephaloglycihe, cefpirome or cefepime or a penem or carbapenem such as imipenem or meropenem, are an object of the present invention. Such combinations are suitable for the control of p-lactamase-forming pathogens. 3 0 The following Examples are intended to illustrate the present invention in more detail, but are not intended to limit its scope in any manner. Example 1 Benzhydryl (2S,3R,5R)-3-formyl-3-methyl-7-oxo-4-thia-1 -aza- bicyclo[3.2.0]heptane-2-carboxylate. 100 ml of dichtoromethane are treated with 0.84 ml (9.6 mmol) of oxalyl chloride under argon and cooled to -60oC. Thereto there are added dropwise 0.73 ml (10.25 mmol) of DMSO, followed by 2.5 g (6.52 mmol) of benzhydryl (2S)3R)5R)-3-hydroxymethyl-3- i o methyl-7-oxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate dissolved in 100 ml of dichloromethane. The mixture is stirred at the same temperature for 3 hours and then 3.2 ml (23.0 mmol) of triethylamine are added. The cooling bath is removed and the mixture is left to warm to room temperature. The orange solution is poured into 1000 ml of 0.2N hydrochloric acid and the aqueous phase is extracted twice with dichloromethane. The organic phases are washed with water and saturated, aqueous sodium chloride solution, dried over sodium sulphate, filtered and concentrated on a rotary evaporator. The thus-obtained product (2.50 g, 100%) can be processed without further purification or can be recrystallized from diethyl ether. Yield: 2.00 g (80%) of white crystal powder; m.p. 111.8-112.80C IR(KBr): 2720, 1788, 1743, 1718 cnH MS: (M-CH2CO) 339 1H-NMR (250MHz, CDCI3): 5[ppm} - 1.26(s,3H), 3.06(dd,1H,J= 16.2Hz, 2Hz, 6-H), 3.54(dd,1H,J-16.2Hz, 4Hz,6-H), 5.34(3,1 H,2-H), 5.42(dd,1H,J-2Hz, 4Hz,5-H)> 6.95(s,1H,CHPh2), 7.30-7.38 (m.lOH.Ph), 9.20(s,1H). t •• Example 2 (a) Benzhydryl (EMaS.aS.SRJ-a--ethoxycarbonyl-vinylJ-S- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 500 mg (1.30 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxy!ate are dissolved in 20 ml of THF under argon and treated with i o 500 mg (1.40 mmol) of ethoxycarbonylmethylene-triphenylphos- phorane. The yellow solution is stirred at 50oC for 75 minutes and subsequently concentrated. The residue remaining behind is ' chromatographed over silica gel (0.040-0.063 mm particle size) with ethyl acetaterhexane 9:16 as the eluent. Yield: 520 mg (88%) of yellow-orange resin; IR (film): 1783, 1747, 1717, 1650 cm-i MS: (M-CONH) 406, (M-CHPh2) 284 -NMR (250MHz, CDCI3): 8[ppm] « 1.31 (t,3H,J-7Hz) ,1.34(s,3H), 3.13(dd,1H,J=2Hz, 16Hz,6-H), 3.57(dd,1H,J=4Hz, 16Hz,6-H), 4.22(q,2H,J=7Hz), 4.78(s,1H,2-H), 5.30(dd,1H,J=4.2Hz, 5-H), 5.97(d,1H,J*15Hz,=GH), 6.94(s,1H,CHPh2), 7.07(d,1H,Ja:15Hz,«CH), 7.30-7.38(m,10H,Ph). (b) Benzhydryl (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3- methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 250 mg (0.55 mmol) of benzhydryl (E)-(2S,3S,5R)-3-(2-ethoxy. carbonyl-vinyl)-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0J- heptane-2-carboxylate are dissolved in 10 ml of dichloromethane and treated with 6.5 ml of glacial acetic acid. 260 mg (1,66 mmol) of potassium permanganate in 25 ml of water are added dropwise to the yellow solution. After completion of the addition stirring is continued for a further 30 minutes and then the brown reaction mixture is treated with a 30% hydrogen per* oxide solution until a colourless two-phase mixture forms. The phases are separated in a separating funnel and the aqueous phase is extracted twice with dichloromethane. The organic phase is washed with water, saturated sodium hydrogen carbonate solution and saturated sodium chloride solution, dried over sodium sulphate, filtered and concentrated. The residual oil is chromatographed over silica gel (particle size 0.040-0.063 mm) with ethyl acetaterhexane 9:16 as the eluent. to Yield: 170 mg (60%) of colourless foam. IR(KBr): 1802, 1757, 1721, 1653, 1331, 960 cm* MS: (M-H) 482.4 iH-NMR (250MHz, CDCI3): 6[ppm] = 1.26(s,3H), 1.35(t,3H,J=7Hz), 3.44-3.59(pseudo-m, 2H, 6-H), 4.29(q,2H,J=7Hz), 4.60(dd,1H, J»4Hz, 2Hz,5-H), 4.61(s,1H,2-H), 5.99(d,1H,J=16Hz,*CH), 6.94(s,1H, CHPh2), 7.07(d,1H,J=16Hz,-CH), 7.23-7.40(m,10H,Ph). (c) Sodium (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3- methyl-4.4.7-trioxo-4-thta-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 170 mg (0.35 mmol) of berizhydryl (E)-(2S,3S,5R)-3-(2-ethoxy- carbonyl-vinyl)-3-methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylate are dissolved in 3 ml of m-cresol under argon and stirred at 50°C for 4.5 hours. Thereafter, the mixture is treated with 12.5 ml of isobutyl methyl ketone and the yellow-orange solution is extracted three times with 3 ml of saturated, aqueous sodium hydrogen carbonate solution each time. The aqueous phase is washed twice with 5 ml of isobutyl methyl ketone each time, filtered over a fluted filter and subsequently adjusted to pH » t with concentrated hydrochloric acid. The mixture is extracted with ethyl acetate, the organic phase is washed with saturated, aqueous sodium chloride solution, dried over sodium sulphate, filtered and concentrated on a rotary evaporator. The residual yellow resin is dissolved in 0.5 ml of c •• ethyl acetate and treated with 108 nl of sodium 2-ethylcaproate (2N solution in ethyl acetate). The mixture is concentrated, the residue is treated with 1.5 ml of water and extracted once with n-hexane. Subsequently, the aqueous phase is chromatographed over polymeric hydrophobic gel with water as the eluent. The fractions containing the product are combined and lyophilized. Yield: 60 mg (50%) of colourless lyophilizate IR(KBr): 1782, 1715, 1627, 1396, 1192 cm-1 MS: (M-Na)- 316.1 iH-NMR (250MHz, D2O); 8[ppm] = 1.31(t,3H,J=7Hz)) 1.66(s,3H), 3.46(dd,1H,J=16Hz, 2Hz,6-K), 3.71(dd,1H,J=16Hz, 4Hz,6-H), 4.28(q,2H,J=7Hz), 4.62(s,1H,2-H), 5.15(dd,1H,J=2Hz)4Hz)5-H), 6.35(d,1H,J=16Hz,=CH))7.10(d,1H,J=16Hz)=CH). Example 3 (a) Benzhydryl (E)-(2S,3S,5R)-3-(2-methoxycarbonyl-vinyl)-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 2 5 200 mg (0.52 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are converted into benzhydryl (E)-(2S,3S,5R)-3-(2-methoxy- carbonyl-vinyl)-3-methyl'7-oxo-4-thia-1-aza-bicycloE3.2.03- heptane-2-carboxylate by reaction with 193 mg (0.58 mmol) of methoxycarbonylmethylene-triphenylphorsphorane according to Example 2. Yield: 209 mg (91%) of colourless foam IR (film): 1782, 1745, 1724, 1651 crrri MS: (M+NH4+) 455.3 « f * Example 4 (a) Benzhydryl (E)-(2S)3S(5R)-3-(2-ben2yloxycarbonyl-vinyl)- 3-methyl-7-oxo-4-thia-1-aza-bJcyclo[3.2.0]heptane-2- carboxylate 763 mg (2.0 mmol) of benzhydryl (2S,3R(5R)-3-formyl-3-methyl- 7-oxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate are dissolved in 15 ml of THF under argon, treated with 821 mg (2.0 mmol) of benzyloxycarbonylmethylene-triphenylphosphorane and the orange solution is stirred at 50oC for 2 hours. It is left to cool to room temperature, the solvent is removed on a rotary evaporator and the red-brown oil is chromatographed over silica gel (particle size 0.040-0.063 mm) with ethyl acetateihexane 9:16 as the eluent. Yield: 800 mg (78%) of orange foam IR (film): 1782, 1746, 1721, 1649, 985 citH MS: (M+H)+ 514.3 1H-NMB (250MHz, CDCI3): 6[ppm] = 1.33(s,3H)f 3.11(dd,1H,J-16Hz, 1.6Hz, 6-H), S.SefddJH.J-ieHz, 4.2Hz, 6-H), 4.78(8,12-, 5.20(s,2H), 5.36(dd,1H, J-1.6HZ, 4.2Hz, 5-H), 6.01(d,1H,J» 15Hz,-CH), 6.93(s,1H,CHPh2), (d.lH.JISHz, «CH), 7.30- 7.43(m,15H,Ph). (b) Benzhydryl (E)-(2S>3S,5R)-3-(2-benzyloxycarbonyl-vinyl)- 3-methyl-4,4,7-trioxo-4-thia'1-aza-bicyclo[3.2.0]heptane- 2-carboxylate 800 mg (1.56 mmol) of benzhydryl (E)-(2S)3S,5R)-3-(2-benzyl- oxycarbonyf-vinyl)-3-methyl-7-oxo-4-thia-1-aza-bicyc1o[3.2.0]- heptane--carboxylate are oxidized according to Example 2. Yield: 255 mg (30%) of colourless foam IR(KBr): 1802, 1757, 1723, 1650, 1332 cm-i MS: (M-H)- 544.2 1H-NMR (250MHz, CDCI3): 8[ppm] = 1.25(s,3H), 3.47(cld>1H,J-1 GHz, 2Hz,6-H), 3.55(dd,1H)J=16Hz, 4Hz, 6-H), 4.66(dd,1H)JaB2Hz, 4Hz>5- H), 4.81(s,1H,2-H), 5.26(3,2, 6.02 (d,1HtJ-16Hz,-CH), 6.93(8,, CHPh2), 7.22(d,1H,J=16Hz)=CH)I 7.13-7.14(m,15H,Ph). (c) Sodium (E)-(2S)3S,5R)-3-(2-benzyloxycarbonyl-vinyl)-3- methyl-4.4.7-trioxo-4-thia-1-aza-bicyelo[3.2.0]heptane-2- carboxylate 250 mg (0.46 rtimol) of benzhydryl (E)-(2S,3S,5R)-3-(2-benzyl- oxycarbonyl-virvyl)-3-methyl-4,4,7-trioxQ-4-thia-1-aza- bicyclo[3.2.0]heptane-2-carboxylate are deprotected according to Example 2. Yield: 54 mg (30%) of beige lyophilizate IR (KBr): 1781, 1719, 1626, 1322, 1189, 979 crrH MS: (M-H)" 378.2 1H-NMR (250MHz, D2O): 5[ppm] = 1.65(s,3H), 3.45(dd,1H,J=17Hz, (dd,1H,1J=4Hz, 2Hz,5-H), 5.29(s,2H), 6.42(d,1HIJ=16HzI=CH), 7.13(d,1H,J=16HzI=CH), 7.42-7.55(m,5H,Ph). Example (a) Benzhydryl (E/Z)-(2$,3S,5R)-3-(2-cyanoethenyl)-3- methyl-7-oxo-4-thia-1-aza-bicyclot3.2.0]heptane-2- carboxylate Method A: 1.0 g (2.62 mmol) of benzhydryl (2S,3Rf5R)-3-formyl-3-methyl- 7-oxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate and ml of toluene are added to 946 mg (3.14 mmol) of cyano- ethylene-triphenylphosphorane under argon. The brown suspen¬ sion is stirred for 1 hour, concentrated and chromatographed over silica gel (particle size 0.040-0.063 mm) with ethyl acetate: n-hexane 3:1 as the eluent. Yield: 1.0 g (94%) of isomer mixture, E:Z 3:1 Spectroscopic data of the mixture: IR (film): 2224, 1781, 1744 cm-1 MS: (M+Na+) 427.2 1H-NMR (250MHz, CDCI3) (E isomer): 5[ppm] = 1.32(s,3H), 3.13(dd,1H,J=16Hz, 1.6Hz, 6-H), 3.63(dd,1H,J=16Hz, 4.4Hz,6-H), 4.74(s,1H,2-H), 5.41(dd,1H,J=4.4Hz, 1.6H,5-H), 5.54(dJ1H,J=15Hz> =CH), 6.82(dJH,J=15Hz,=CH), 6.95(s,1H,CHPh2), 7.30-7.44(m,10H, Ph). 1H-NMR (250MHz, CDCI3) (Z isomer): 5[ppm] . 1.61(s,3H), 3.18(dd,1H,J=16Hz,1.5Hz,6-H), 3.64(dd,1H,J=16Hz, 4.6Hz,6-H), 4.86(S,1H,2-H), 5.41(d,1H,J=12Hz,=CH), 5.44,1 H,J=1.5Hz, 4.6Hz,5-H), 6.63(d,1H,J-12Hz,=CH), 6.95(s,1H,CHPh2), 7.30- 7.44(m,10H,Ph). Method B: A suspension of 2.88 g (9.56 mmol) of cyanomethylene-tri- phenylphosphorane in 24 ml of lithium perchlorate solution (0.4M in acetonitrile) is cooled to -20oC under argon. A solution of 3.32 g (8.70 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3- methyl-7-Qxo-4-thia-1-aza«bieyclo[3.2.03heptane-2-carboxylate in 30 ml of acetonitrile is added dropwise thereto, the mixture • a * is stirred at the same temperature for 4 hours and the solvent is removed on a rotary evaporator. The residue remaining behind is taken up in 100 ml of ethyl acetate, extracted three times with water and once with saturated sodium chloride solution, dried over magnesium sulphate, filtered and concentrated. The residual oil is purified over silica gel (particle size 0.040-0.063 mm) with methylene chloride as the eluent. Yield: 3.34 g (94%) of isomer mixture, E:Z 1:4 (b) Benrhydryl (E/Z)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carbox- ylate Benzhydryl (E/Z)-(2S,3SI5R)-3-(2-cyanoethenyl)-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate is prepared in the same manner as described in Example 2 by oxidizing benzhydryl (E/Z)-(2S,3S,5R)3-(2-cyanoethenyl)-3- methyl-7-oxo-4-thia-1-aza-bicyclo{3.2.0]heptne-2-carboxylate. 2 0 The two isomers can be separated by chromatography over silica gel (particle size 0.040-0.063 mm) with ethyl acetatehexane (9:16). The Z isomer is eluted as the first component. Yield: Z: 76 mg (7%) of colourless oil E: 253 mg (23%) of colourless foam Spectroscopic data E isomer: MS: (M+NH4)+454.2 1R (KBr): 2228, 1802f 1758, 1334, 1192, 990 cm-i ao -NMR (250MHz, CDCI3): 8[ppm] » 1.24(8.3, 3.50(dd,1H,J-16Hz, 2.2H2,6-H), 3.60(dd,1H,J«16Hz, 4Hz,6-H), 4.65(dd,1H,J-2Hz, 4H2,S-H), 4.7S(s,1H,2-H), 5.37(d,1H,J=16H2,=CH), 6.85(d,1H,J= 16Hz,.CH), e.gS.IH.CHPh, 7.25-7,45(m,10H,Ph). Spectroscopic data Z isomer: MS: (M-H)- 435.3 IR (KBr): 2220, 1801, 1757, 1333, 1190 cm"1 1H-NMR (250MHz, CDCI3): 8[ppm] - 1.67(s, 3H), 3A8(6d, 1H, J=16Hz, 2.4Hz, 6-H), 3.64<dd, 1H, J-16Hz, 4.6Hz, 6-H), 4.72(dd, 1H, J=2.4Hz, 4.6Hz, 5-H), 4.85(s,1H, 3-H), 5.90(d,1H,J*12Hz,=CH), iO 6.41(d,1H,J«12Hz, «CH), 6.97(s,1H,CHPh2), 7.26-7.44(m,10H,Ph). (c) Sodium (E)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 215 mg (0.5 mmol) of benzhydryl (E)-(2S,3S,J;R)-3-(2-cyano- ethenyl)-3-methyi'4,4,7-tfioxo-4-thia-1-aza-bicyclo[3.2.0]- heptane-2-carboxylate are deprotected according to Example 2. Yield: 110 mg (82%) of white lyophilizate IR (KBr): 2240, 1782, 1629, 1397, 1141 cm-i 1H-NMR (250MHz, CDCI3): 5[ppm] - 1.64(s,3H), SddJH.JISHz, 2 5 2Hz,6-H), 3.72(dd,1H,J=16Hz, 4Hz,6-H), 4.62(s,1Hs2-H), 5.15 (dd,1H,J-2Hz,4Hz,5-H), 6.07(d,1H,J=16Hz,=CH), 7.08(d,1H,J- 16Hz,=CH). Sodium (Z)-(2S,3S,5R)-3-(2-cyanoettienyl)-3-methyl-4,4,7- trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-Garboxylate 95 mg (0.2 mmol) of benzhydryl (Z)-(2S13S,5R)-3-(2-cyano- ethenyl)-3-methyl-4,4,7-trioxo-4-thia-1-aza-bieyclo[3.2.0]- heptane-2-carboxylate are dissolved in 3 ml of m-cresol and stirred at 50°C for 45 minutes. The reaction mixture is treated with 10 ml of isobutyl methyl ketone and 120 jil of sodium 2- ethylcapfoate (2N in ethyl acetate, 1.1 eq.). The mixture is extracted twice with 3 ml of water each time, the combined aqueous phases are washed with 10 ml of isobuty! methyl ketone and lyophilized. The yellow lyophilizate is dissolved in 1.3 ml of water and chromatographed over polymeric hydrophobic gel. Yield: 50mg (80%) of colourless lyophilizate IR (KBf): 2222, 1782, 1626, 1395, 1323, 1141 cm"1 1H-NMR (250MHz, D2O): 8[ppm] = 1.94(s,3H), 3.47(dd,1H,J«16Hz, 1.6Hz, 6-H), 3.73(dd, 1H, J=16Hz, 4.4Hz, 6-H), 4.80(8,,2-, 5.19(dd, 1H, J=1.6Hz, 4.4Hz,5-H), 6.15(d.1H,J=12Hz,=CH), 6.68 (d,1H,J=12Hz,=CH). t5 Example 6 (a) Benzhydryl (E/Z)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 2.60 g (6.86 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3-methyl- 7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate and 2.15 g (6.86 mmol) of carbamoylmethylene-triphenylphosphorane are suspended in 60 ml of THF under argon and stirred at 50oC for minutes. Insoluble material is filtered off under suction and the filtrate is concentrated on a rotary evaporator. The brown oil is chromatographed on silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 1:1 as the eluent and the two isomers are separated. The 2 isomer is eluted before the E isomer, both can be obtained as crystalline solids from CH2Cl2:n-hexane. Z isomer: Yield: 217 mg (7.5%) of colourless solid i 5 IR (KBr): 3441, 1777, 1743, 1678, 986 cm-1 MS: (M-CHPh2) 25$ • •r-« k • M.p.: 188-1890C 1H-NMR (250MHz, CDCI3): 8[ppml = 1.58(s,3H), a.ldd.lH.J-IBHz, 1.60Hz,6-H), 3.57(dd,1H)J*16Hz, 4.40Hz,6-H), 5.2a(s,1H,2-H), 5.36(dd,1H,J-4.40Hz, I.BOHz.S-H), 5.5(pseudo-dl2HlNH2), 5.75 (d.lH.J-Hz.-CH), 6.24(d)1HlJ-12Hz)-CH)) Ss.lH.CHPhg), 7.29-7.43(m,10Hl Ph). E isomer: Yield: 347 mg (12%) of crystalline solid IR (KBr): 3444, 1775, 1728, 1671 cm-1 1 5 MS: (M+H)+ 423.4 M.p.: 1420C (dec.) "•H-NMR (250MHz, CDCI3): 8 - 1.36(5,3, 3.11=(dd,lH,J-16HzI' 2.0Hz,6-H), S.SSdd.lH.JIBHz, 4.2Hz,6-H)) 4.83(s,1H,2-H), 5.37(dd>1H,J=2.0Hz, 4.2Hz,5-H)) 5.55(sfbrl2HlNH2)l 5.97(d,1H, J-15Hz,»CH), 6.94(s,1H,CHPh2), 6.95(d)1H,J=15Hz,-CH), 7.28- 7.40(m,10H,Ph). 2 5 (b) Benzhydryl (Z)-(2S)3S)5R)-3-(2-carbainoyl-vinyl)-3- methyl-4,4,7-trioxo-4-thia"1-aza-bicyclo[3.2.0]heptan6-2' carboxylate 370 mg (0.875 mmdl) of benzhydryl (Z)-(2S,3S)5R)-3-(2- carbamoyl-Yinyl)-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]- heptane-2-carboxylate are oxidized in accordance with Example 2. A mixture of ethyl acetate:n-hexane 1:1 is used as the eluent. Yield: 225 mg (37%) of colourless foam IR (KBr): 1799, 1750, 1678, 1326, 1188, 1140 errH MS; (M+H)+ 455.2 iH-NMR (250MHz, CDCI3): 8[ppm] - LSCKs.SH), 3.45(dd,1H,J-16H aHz.S-H), S.SStdd.lKJ-ieHz, 4HzI6-H), 4.67(dd>1H,J-4Hz, 2Hz,5- H), SSfs.lH.a-H), 5.63(sfbr,1H)NH2), 5.84(d,1H,J=13Hz,=CH), 6.69 (s,brf1H,NH2), 6.39(d,1H>J=13HzI-CH), 6.93(s,1H,CHPh2), 7.29- 7.41(m,10H,Ph). Benzhydryl (E)-(2S,3S,5R)-3-(2-Carbamoyl-vinyl)-3-methyl- 1 0 4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate 0.64 g (1.51 mmol) of benzhydryl (E)-(2S>3R>5R)-3-(2-carbam- oyl-vinyl)-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane- 2-carboxylate are dissolved in 30 ml of methylene chloride and cooled to 0oC. 1.86 g (7.55 mmol) of meta-chloroperbenzoic acid (content: 70-75%, 5 eq.) in 30 ml of methylene chloride are added dropwise thereto, the cooling bath is removed after completion of the addition and the mixture is stirred at room temperature for 6 hours. The reaction solution is extracted with sodium sulphite solution (30% in saturated aqueous sodium bicarbonate solution) and washed with saturated aqueous sodium chloride solution. The solution is dried over magnesium sulphate, filtered, the solvent is removed on a rotary evaporator and the residue remaining behind is recrystallized using methylene chloride:n-hexane. Yield: 210 mg (30%) of colourless solid IR (KBr): 1799, 1756, 1686, 1329, 1143, 1191 cnH MS: (M+H+) 455.3 M.p.r 186-1880C 1H-NMR (250MH2, CDCI3): 5[ppm] - 1,30(8,31-0, 3.47(dd,1H,J*16Hz, 3.0Hz,6-H), 3.61(dd,1H>J=l6m, 4.4Hz,6-H), 4.67(dd>1H,J«3.0Hz, 4.4H2,5-H), 4.82(8,,2-, 5.53(s,br,2H,NH2), e.QSfd.lH, J-16H2,*CH), 6.98(d,lH,J.16H2,*CH), 6.94(8,1 H,CHPh2), 7.26- 7.4O(m,10H,Ph). (c) Sodium (Z)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 135 mg (0.30 mmol) of benzhydryl (Z)-(2S,3S,5R)-3-(2-car- bamoyl-vinyl)-3-methyl-4,4.7-trloxo-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylate are deprotected according to Example 2. Yield: 67 mg (70%) of colourless lyophilizate IR (KBr): 3434, 1781, 1668, 1626, 1397, 1317, 1139 cm"1 1 5 MS: (M-Na)" 287.2 -NMR (250MHz, D2O): 8[ppm] = 1.76(s,3H), 3.44(dd,1H,J=16Hz, 1.2Hz,6-H), 3.69(s,1 H,J=16Hz, 4Hz,6-H), 4.68(s,1H,2-H), 5.10 (dd,1H,J=4Hz, 1.2Hz,5-H), 5.94(d,1H,J=13Hz,=CH), 6.53 (d,1H, 2 0 J=13Hz,=:CH). Sodium (E)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-methyl-4.4.7- trioxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate 350 mg (0.78 mmol) of benzhydryl (E)-(2S,3S,5R)-3-(2-car- bamoyl-vinyl)-3-methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo- [3.2.0]heptane-2*carboxylate are deprotected according to Example 2. Yield: 190 mg (80%) IR (KBr): 1782, 1684, 1622, 1398, 1318, 1140 cm-1 MS: (M-Na)' 287.2 fH-NMR (250MH2, D2O): 5[ppmJ * 1.66(S,3H), 3.46(ddl1H,J*l7H2, 1.4H2, 6-H), 3.71(dd, 1H, J-t7H2, 4.0H2,6-H), 4.62(s,lH,2-H), »• t 5.14(dd,J-1.4Hz, OHz.S-H), ed.lH.J-ISHzGH), 6.88(d,1H,J«16Hz,=CH). Example 7 (a) Benzhydryl (EHaS.aS.SRJ-S--ethoxycarbonyl-propenyl)- 3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 286 mg (0.75 mmoi) of benzhydryJ (2S,3R,5R)-3-formyl-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptan-2-carboxylate are dissolved in 12 ml of THF under argon and treated with 271 mg (0.75 mmol) of (l-ethoxycarbonylethylidene)-triphenyl- phosphorane. The yellow solution is stirred at 70oC for 6 hours and subsequently concentrated. The residue remaining behind is chromatographed over silica gel (0.040-0.063 mm particle size) with ethyl acetaterhexane 9:16 as the eluent. Yield: 157 mg (45%) of pale yellow solid IR (film): 1788, 1754, 1704, 1642 cm-i MS: (M+NH4+)483.4 1H-NMR (400MHz, CDCI3): 8[ppm] . 1.32(t,3H,J*7.1Hz) ,1.38(s,3H), 2.03(d,3H,J-1.5Hz), 3.05(dd,1H,J«1.8Hz, 16Hz,6-H), 3.57(dd,1H, J-4.3HZ, leHz.eH), 4.23(q,2H,J-7.1Hz)) 4.89(8,12), 5.29(dd, 1H,J»4.3, 1.8Hz,5-H), 6.94(s,1H,CHPh2), 7.20(d,1H,J*1.5Hz,=CH), 7.30-7.36(m,10H,Ph). Example 8 (a) Benzhydryt (E,Z)-(2S,3$,5R)-3-(2-chloro-vinyl)-3-methyl- 7-oxo-4-thia«1-aza-bicyclo[3.2.G]heptane-2-carboxylate A suspension of 1.37 g (4.40 mmol) of chloromethylene- triphenylphosphorane in 25 ml of diethyl ether is cooled to 0oC and treated with 1.60 g (4.20 mmol) of benzhydryl (2S,3R,5R)-3- formyl-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate. The cooling bath is removed and the mixture is stirred at room temperature for a further 3 hours. The orange suspension is filtered and subsequently concentrated. The residue remaining behind is chromatographed over silica gel (0.040-0.063 mm particle size) with ethyl acetate:hexane 1:2 as the eluent. Yield: 1.20 g (69%) of yellow isomer mixture, E:Z 7:9 Spectroscopic data of the mixture: IR (film): 1782, 1747, 1590, 1496, 1251 cm*1 MS; (M+NH4+)413 (b) Benzhydryl (E/Z)-(2S,3S,5R)-3-(2-chlorQ-vinyl)-3-methy{- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carbox- ylate 2.98 g (14.05 mmol) of sodium metaperiodate are dissolved in ml of water under argon and cooled to 0°C. The solution is treated with 0.93 g (11.17 mmol) of sodium bicarbonate followed by 45 ml of acetonitrile as well as 60 ml of methylene 2 5 chloride. 9 mg (0.070 mmol) of ruthenium dioxide and subse¬ quently the solution of 1.20 g (2.90 mmol) of benzhydryl (E/Z)- (2S,3S,5R)-3-(2-chloro-vinylh3-methyl-7-oxo-4-thia-1-aza- bicyclo[3.2.0]heptane-2-carboxylate are added to the two-phase mixture. The cooling bath is removed and the reaction mixture is 3 0 stirred until the reaction has finished (tic control). Subse¬ quently, the mixture is treated with 2 g of active charcoal and ml of saturated sodium chloride solution, stirred for minutes and suction filtered over Dicalite. The phases are separated in a separating funnel, the aqueous phase is extracted 3 5 twice with methylene chloride and the combined organic extracts are washed with water and saturated sodium chloride solution, dried over magnesium sulphatetfuller's earth, filtered and evaporated. The residual oil is chromatographed over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 1:2 a « • t « as the eluent, the two isomers being separated in this manner. The Z isomer is eluted as the first component. Yield: Z: 495 mg (38%) of colourless foam E: 385 mg (30%) of colourless foam Spectroscopic data E isomer: 1 0 MS: (M+NH4)+ 463.4 IR (KBr): 1800, 1756, 1612, 1331, 1143, 700 cm-t Spectroscopic data Z isomer: MS: (M+NH4)+ 463.4 IR (KBr): 1800, 1755, 1630, 1330, 1143, 700 cm-1 (c) Sodium (E)-(2S,3S,5R)-3-(2-ch\oro-v\i)y\)'Z-methy\-4AJ~ trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 385 mg (0.86 mmol) of benzhydryl (E)-(2S)3S)5R)-3-(2-chloro- vinyl)-3-methyi-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]- 2 5 heptane-2-carboxylate are dissolved in 2.3 ml of m-cresol under argon and stirred at 50oC for 4 hours. Subsequently, the mixture is diluted with 15 ml of isobutyl methyl ketone, treated with 0.50 ml of sodium 2-ethylcaproate (2N solution in ethyl acetate) and extracted three times with 8 ml of water each time. The combined aqueous phases are washed once with 10 ml of isobutyl methyl ketone, lyophilized and the lyophilizate obtained is chromatographed over polymeric hydrophobic gel with water as the eluent. 3 5 Yield: 57 mg (32%) MS: (M-Na)" 278.2 IR (KBr): 1780, 1626, 1564, 1417, 1329, 1145 cm-1 t « Sodium (Z)-(2S,3SI5R)-3-(2-chloro-vinyl)-3-methyl-4I4I7- trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 400 mg (0.90 mmol) of benzhydryl (Z)-(2S,3SI5R)-3-(2-chloro- vinyl)-3-methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]- heptane-2-carboxylate are deprotected according to Example 8. Yield: 176 mg (65%) of colourless lyophilizate 1 0 MS: (M-Na)" 278.2 IR (KBr): 1779, 1626, 1398, 1321, 1142 cm-1 Elementary analysis: CgHgCINOsSNa (301.676) Calc. C 35.83 H 3.01 N 4.64 Found#) C 35.72 H 3.04 N 4.65 2 0 #) anhydrous, calculated with 5.53 % water Eyampte 9 (a) (E)-(2S,3S,5R)-3-methyl-7-oxo-3-(3-oo-but-1-enyl)-4- thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 381 mg (1.00 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are dissolved in 12 ml of THF under argon and treated with 350 mg (1.10 mmol) of acetylmethylene-triphenylphosphorane. The mixture is stirred at 50°C for 6 days and subsequently concentrated. The residue remaining behind is chromatographed over silica gel (0.040-0.083 mm particle size) with ethyl acetate:methylene chloride 95:5 as the eluent. Yield: 221 mg (52%) of white resin »R (film): 1782, 1681, 1627, 1319, 1141, 980 em-1 MS: (M-Na)-286.1 » a (b) Benzhydryl (EMaS.SS.SRJ-a-methyl-a-ta-oxo-but-l-enyl)- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 221 mg (0.49 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-7- oxo-3-(3-oxo-but-1-enyl)-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate are oxidized according to Example 8. Chromatography is carried out once over silica gel (particle size 0.040-0.063 mm) io with ethyl acetate:n-hexane 9:16 as the eluent and crystallization is carried out from methylene chloride/n-hexane. Yield: 95 mg (40%) of colourless crystals MS; (M+NH4)+471.2 IR (KBr): 1798, 1760, 1682, 1627, 1330, 1193, 1142, 976 cm-1 M.p.: 183-1840C (c) Sodium (E)-(2S,3S,5R)-3-methyl-3-(3-oxo-but-1-enyl)- 4,4J-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 250 mg (0.55 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-3- (S-oxo-but-l-enyOJ-trioxo-thia-l-aza-bicyclotS.O)- heptane-2-carboxylate are deprotected according to Example 8. Yield: 47 mg (27%) of colourless lyophilizate MS: (M-Na)" 286.1 IR (KBr): 1782, 1681, 1627, 1394, 1319, 1141, 980 cnr1 Example (a) (EMaSS.SRJ-a-Ca-Formyl-vinyO-S-methyl-y-oxo--*- thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 3.81 g (10.0 mmol) of benzhydryl (2S,3RI5R)-3-formyl-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are dissolved in 40 ml of methylene chloride under argon and treated with 3.34 g (11.0 mmol) of formylmethylene-triphenyl- 1 o phosphorane. The yellow solution is stirred at room temperature for 3 days and subsequently concentrated. The residue remaining behind is chromatographed over silica gel (0.040-0.063 mm particle size) with tert.butyl methyl ethern-hexane 2:3 as the eluent. Yield: 528 mg (13%) of colourless resin IR (film): 2738, 1781, 1744, 1717, 1690, 1496, 1178, 986 cm-i MS: (M+MH4+) 425.6 Example 11 (a) Benzhydryl (E)-(2S,3S,5R)-3-methyl-3-[2-(1,2,4-oxadia- 2 5 zol-3-yl)-vinyl]-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 1.14 g (3.0 mmol) of benzhydryl (2S,3R,5R)-3-formyt-3-methyl- 7-oxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate are dissolved in 15 ml of 1,2-butylene oxide, treated with 1.38 g (3.6 mmol) of (1,2,4-oxadiazol-3-yl)methyl-triphenylphos- phonium chloride and refluxed for 10 hours. Subsequently, the mixture is filtered, the filtrate is evaporated and the residual brown oil is chromatographed over silica gel (0.040-0.063 mm particle size) with methylene chloride as the eluent. Yield: 280 mg (21%) of colourless crystals MS: (M+NH4)+ 465.3 IR (KBr): 1792, 1753, 1658, 1492, 1200, 991 cm-1 (b) Benzhydryl (E)-(2S,3S,5R)-3-methyl-3-[2-(1,2,4- oxadiazol-3-yl)-vinyl]-4,4,7-trioxo-4-thia-1 -aza- bicyclo[3.2.0]heptane-2-carboxylate 280 mg (0.63 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-3- [2-(1,2,4-oxadiazol-3-yl)-vinyl]-7-oxo-4-thia-1-aza-bicyclo- 1 o [3.2.0]heptane-2-carboxylate are oxidized according to Example 8. Chromatography is carried out once over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 9:16 as the eluent and crystallization is carried out from methylene chloride/n- hexane. Yield: 95 mg (40%) of colourless crystals MS: (M-H)- 478.3 IR (KBr): 1805, 1758, 1650, 1334, 1196 cnr"! M.p.: 1570C Elementary analysis: C24H2iN3O6S(479.507) Calc. C 60.12 H 4.41 N 8.76 Found G 59.94 H 4.26 N 8.55 (c) (E)-(2S,3S,5R)-3-methyl-3-[2-(1,2,4-oxadiazor-3-yl)- vinyl]-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.Q]hept&ne-2- 3 0 carboxylic acid 355 mg (0.74 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-3-I2- (1,2,4-oxadiazol-3-yl)-vinyl]-4,4,7-trioxo-4-thia-1 -aza- bicyclo[3.2.0Jheptane-2-carboxylate are dissolved in 3 ml of m- cresol and stirred at 50oC for 4 hours. 20 ml of n-hexane are added to the pale brown solution, the separated crystals are filtered off under suction and rinsed with n-hexane. The crude crystallizate is recrystallized from ethyl acetate/n-hexane. ft • • • • a Yield: 170 mg (73%) of colourless crystals MS: (M-H)- 312.2 IR (KBr): 2900(50, 1811, 1714, 1660, 1331, 1194, 980 cm-1 M.p.: 16l0C(dec.) Elementary aanalysis: CnHnNsOeS (313.284) Calc. C 42.17 H 3.54 N 13.41 Found C 42.41 H 3.64 N 13.18 (c) Sodium (E)-(2S,3S)5R)-3-methyl-3-[2-(1,2,4-oxadia2ol-3- 1 5 yl)-vinyl]-4,4,7-tri0xo-4-thia-1 -aza-bicyclo[3.2.0]heptane- 2-carboxylic acid 85 mg (0.27 mmol) of (E)-(2S,3S,5R)-3-methyl-3-[2-(1,2,4- oxadiazol-3-yl)-vinyl]-4,4,7-trioxo-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylic acid are added in one portion to a clear solution of 23 mg (0.27 mmol) of sodium hydrogen carbonate in 10 ml of water, the mixture is stirred for about minutes, filtered and lyophilized. Yield: 90 mg (91%) of colourless lyophilizate MS: (M-Na)" 312.2 IR (KBr): 1787, 1627, 1395, 1321, 1192, 970 cnr1 Elementary analysis: CnHioNsOeSNa (335.266) Calc. C 39.41 H 3.01 N 12.53 Found#) C 39.86 H 3.04 N 12.51 #) anhydrous, calculated with 5.82% water . 39 - Example 13 (a) Benzhydryl (E) and (Z)-(2S,3S,5R)-3-methyl-3-(2-thiazol- 2-yl-vinyl)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 1.14 g (3.0 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3-methyl- 7-oxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate are dissolved in 50 ml of 1,2-butylene oxide, treated with 1.53 g (3.86 mmol) of (thiazol-2-yl)methyl-triphenylphosphonium chloride and refluxed for 40 hours. Subsequently, the mixture is filtered, evaporated and the brown residue remaining behind is chromatographed over silica gel (0,040-0.063 mm particle size) with methylene chlorideiethyl acetate 95:5 as the eluent. The two isomers are separated in this manner, the Z isomer being eluted as the first component. Z isomer: :';::# 2 0 Yield: 240 mg (17%) of yellow oil IR (film): 1778, 1743, 1493, 1197, 986 cm-1 MS: (M+H+) 463.5 E isomer: Yield: 855 mg (62%) of yellow resin IR (KBr): 1779, 1746, 1492, 1292, 988 cm-1 MS: (M+H)+ 463.5 .:.* (b) Benzhydryl (EJ-faS.SS.SRJ-S-methyl.T-trioxo-Sa- thiazol-2-yl-vinyl)-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 200 mg (0.43 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-3- (2-thiazol-2-yl-vinyl)-7-oxo-4-thJa-1-aza-bicyclo[3.2.0]- heptane-2-carboxylate are oxidized according to Example 8. Chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with methylene chloride:ethyl acetate 95:5 as i o the eluent. Yield: 72 mg (33%) colourless foam MS: (M+H)+ 495.4 I.R (KBr): 1799, 1756, 1329, 1192, 1142, 963 cm""* Benzhydryl (Z)-(2S,3S,5R)-3-methyl-4,4,7-trioxo-3-(2-thiazol- 2-yl-vinyl)-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 210 mg (0.45 mmol) of benzhydryl (Z)-(2S,3S,5R)-3-methyl- 4,4,7-trioxo-3-(2-thiazol-2-yl-vinyi)-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylate are oxidized according to Example 8. Chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with methylene chloride:ethyI acetate 95:5 as the eluent. Yield: 72 mg (33%) of colourless foam 3 0 MS: (M+H)+495.4 IR (KBr): 1793, 1754, 1490, 1328, 1184, 1142, 963 cm-1 (E)-(2S,3S,5R)-3-Methyl-4,4,7-trioxo-3-(2-thiazol-2-yl-vinyl). 3 5 4-thia-t-aza-bicyclo[3.2.0]heptane-2-carboxylic acid 200 mg (0.40 mmol) of benzhydryl (E)-(2S,3S,5R)-3-m6thyh3'' (2-thiaiof-2-yl-vinyl)-4,4,74rioxo-4-thia-1-aza-bicyclo- * V9 [3.2.0]heptane-2-carboxylate are deprotected analogously to Example 11. Yield: 53 mg (40%) of colourless crystals MS: (M+H)+ 329.4 IR (KBr): 2800(br), 1791, 1740, 1634, 1321, 1142, 965 cm-1 Sodium (E)-(2S,3S,5R)-3-methyl-4,4,7-trioxo-3-(2-thiazol-2- yl-vlnyl).4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 53 mg (0.16 mmol) of (E)-(2S,3S,5R)-3-methyl-4,4,7-trioxo-3- (2-thia2ol-2-yl-viny1)-4-thia-1-a2a-bicyclo[3.2.0]heptane-2- carboxylic acid are converted into the corresponding sodium salt analogously to Example 11. Yield: 55 mg (98%) of colourless lyophilizate 2 0 IR (KBr): 1778, 1627, 1392, 1318, 1192, 1141, 955 cm-1 Elementary analysis: Ci2HiiN205S2Na (350.339) Calc. C 41.14 H 3.16 N 8,00 Found#) C 40.73 H 3.51 N 7.92 it} anhydrous, calculated with 5.9% water Sodium (Z)-(2S,3S,5R)-3-methyl-4,4)7-trioxo-3-(2-thiazol-2- yl-vinyl)-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 160 mg (0.32 mmol) of benzhydryl (Z)-(2S,3S,5R)-3-methyl- 4,4,7-tfloxo-3-(2-thiazol-2-yl-vinyl)-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylate are converted into the corres* ponding sodium salt analogously to Example 8. Yield: 60 mg (57%) of colourless lyophilizate |R (KBr): 1781, 1623, 1398, 1320, 1193, 1140, 950 cm-1 1H-NMR (250MHz, CDCI3): 8[ppm] = 1.52(s,3H), Sdd.lH.J-iSHz, IHz.S-H), 3.58(dd,1HIJ=16HzI 4.1Hz,6-H), 5.04(dd,1H,J=1.2Hz, 4.1Hz,5-H), 5.19(s,1H,2-H)f 6.06(d,1H,J=12.5Hz,=CH), 7.14(d,1H,J= 12.5Hz,=CH), 7.75(AB system,2H,J=3.5Hz, thiazole-H). Example 13 (a) Benzhydryl (E)-(2SI3SI5R)-3-methyl-3-{2-pyridin.2-yN vinyl)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate A suspension of 353 mg (1.0 mmol) of (2-picolyl)methylene- triphenylphosphorane and 381 mg (1.00 mmol) of benzhydryl (2S,3R,5R)-3-formyh3-metHyl-7-oxo-4-thia-1-aza'bicyclo- [3.2.0]heptane-2-carboxylate in 10 ml of diethyl ether is stirred at room temperature under argon for 2 hours. The mixture is 2 0 treated with 10 mi of methylene chloride, insoluble material is removed by suction filtration and the filtrate is concentrated. The residue remaining behind is chromatographed over silica gel (particle size 0.040-0.063 mm) with methylene chloride:ethyl acetate 95:5 as the eluent. Yield: 128 mg (28%) of a colourless foam MS: (M*) 456 3 0 IR (KBr): 1779, 1747, 1634, 1291, 988 cm-1 (b> Benzhydryl (E)-(2S,3S,5R)-3-methyl-3-(2-pyridin'2-yl- vinyl)-4,4»7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 196 mg (0.43 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-3- (-pyridin-S-yl-vinyO-oxo-thia-laza-bicycloIS.a.O]- heptane-2-carboxylate are oxidized according to Example 8. Chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with methylene chlorideiethyl acetate 95:5 as the eluent. Yield: 130 mg (62%) of colourless foam MS: (M+H)+ 489.4 IR (KBr): 1799, 1756, 1580, 1490, 1327, 1184, 1141, 969 cnH (c) (E)-(2S,3S,5R)-3-Methyl-3-(2-pyridin-2-y|-vinyl)-4)4)7- trioxo-4thia-1-a2a-bicyclo[3.2.0]heptane-2-carboxylic acid 200 mg (0.41 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-3- (2-pyridin-2-yl-vinyl)-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]- heptane-2-carboxylate are deprotected analogously to Example 10. Yield: 85 mg (65%) of pale beige crystal powder MS: (M+H)+ 323.3 IR (KBr): 2700(br), 1790, 1720, 1621, 1318, 1140, 978 cm-1 Sodium (E)-(2S,3S,5R)-3-methyl-3-(2-pyridin-2-yl-vinyl)-4,4,7- trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid 83 mg (0.17 mmol) of (E)-(2S,3S,5R)-3-methyl-3-(2-pyridin-2- yl-vinyl)4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxyllc acid are converted into the corresponding sodium salt analogously to Example 10. Yield: 89 mg (100%) of colourless tyophilizate IR (KBr): 1784, 1629, 1587, 1478, 1396, 1320, 1187, 1141, 980 cm-1 , 44 - Elementary analysis: CuHisNaOsSNa (344.317) Calc. C 48.84 H 3.81 N 8.14 Found#) C 49.18 H 4.23 N 8.17 #) anhydrous, calculated with 6.86% water Example 14 (a) Benzhydryl (E)-{2S,3S,5R)-3-[2-(methoxy-methyl-carbam- oyl)-vinyl]-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]- heptane-2-carboxylate An orange solution of 1.14 g (3.0 mmol) of benzhydryl (2S,3R,5R)-3-formyl-<3-methyl-7-oxo-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylate and 1.14 g (3.15 mmol) of (N- methoxymethylaminocarbonylmethylenej-triphenylphosphorane is stirred at room temperature under argon for 3 days. The solvent is removed on a rotary evaporator and the residue is chrbmato- graphed over silica gel (particle size 0.040-0.063 mm) with ethyl acetatern-hexane 1:1 as the eluent. Yield: 1.12 g (80%) of colourless foam MS: (M+H)+ 467.4 IR (KBr): 1781, 1744, 1662, 1629, 995 cm-1 (b) Benzhydryl (E)-(2S,3Sf5R)-3-[2-(meth0xy-methyl- carbamoyl)-vinyl3-3-methyl-4,4,7-trioxo-4-thia-1-aza- bicyc1o[3.2.0]heptane-2-carboxylate 0.69 g (1.48 mmol) of benzhydryl (E)-(2S,3S,5R)-3-C2-{methoxy- methyl-carbamoyl)-vinyl]-a-methyl-7-oxo-4-mia-1*aza- bicyclo[3..0]hepmnf-J-carb@icy!m# is oxidized in analogy to Example g. OhmTnatography is carried out over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 3:2 as the eluent. Yield: 405 mg (55%) of colourless foam MS: (M+H)+ 499.4 IR (KBr): 1807, 1753, 1662, 1624, 1318, 1140, 1000 cm-1 (c) Sodium (E)-(2S,3S,5R)-3-[2-(methoxy-methyl-carbamoyl)- vinyl]-3-methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]- heptane-2-carboxylate. 200 mg (0.40 mmol) of benzhydryl (E)-(2S,3S,5R)-3-[2- (methoxy-methyl-carbamoyl)-vinyl]-3-methyl-4,4,7-trioxo-4- thia-1-aza-bicyclo[3.2.03heptane-2-carboxy!ate are deprotected according to Example 8. Yield: 95 mg (67%) of colourless tyophilizate MS: (M+H)+ 355.3 IR (KBr): 1785, 1650, 1626, 1390, 1322, 1191, 1141, 980 crrr"! Elementary analysis: CizHislSteO/SNa (354.309) Calc. C 40.68 H 4.27 N 7.91 Found*) C 40.37 H 4.35 N 7.84 ♦:**•:' 3 0 #) anhydrous, calculated with 2.74% water mmom * *1 Example (E)-(2S,3S,5R)-3-Methyl-3-[2-(1-methyl-pyridin-2-ylio)-vinyl]- 4,4,7-trioxo-4-thta-1-aza-bicyclo[3.2.0]heptan-2-carboxylic acid 150 mg (0.31 mmol) of benzhydryl (E)-(2S,3S,5R)'3-methy1-3- (2-pyridin-2-yl-vinyr)-4,4,7-trioxo-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylic acid are dissolved in 3 ml of 1 o methylene chloride, cooled to 0oC and treated with 56 l (0.51 mmol) of methyl trifluoromethylsulphonate. The cooling bath is removed and the mixture is stirred at room temperature for 2 days. The solvent is removed on a rotary evaporator and the residue fs dried in a high vacuum. The thus-obtained product (200 mg, 100%) is processed without further purification. The brown resin is dissolved in 2 ml of m-cresol and stirred at 50oC for 2 hours. Thereafter, the mixture is treated with 10 ml of isobutyl methyl ketone as well as 5 ml of water, shaken, the phases are separated and the organic phase is extracted twice 2 0 with 5 ml of water. The aqueous phases are washed twice with ml of isobutyl methyl ketone each time, filtered and lyoph- ilized. The yellowish lyophilizate is chromatographed over polymeric hydrophobic gel with water as the eluent. 2 5 Yield: 105 mg (72%) of orange lyophilizate IR (KBr): 1778, 1627, 1377, 1185, 970 cm-i MS: (M+) 337.4 Example 16 (a) Benzhydryl (1E,3E)-(2S,3S,5R)-3-(4-formyl-buta1,3- dienyl)-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]- heptan6-2-Garb0xylate Benzhydryl (1 E,3E)'(2S,3S,5R)-3-(4-formyl-buta-1,3-dienyl)-3- methyl-7-oxo-4-thia-1-t2a-bieyGloC3.2.0lheptane-2-carbsxylate #* * is prepared in analogy to Example 9 from 3.81 g (10.0 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3-methyl-7-oxo-4-thia-1 -aza- bicyclo[3.2.0]heptane-2-carboxylate and 4.55 g (15.0 mmol) of formylmethylene-triphenylphosphorane. Chromatography is carried out over silica gel (0.040-0.063 mm particle size) with methylene chloride:ethyl acetate 98:2 as the eluent. Yield; 347 mg (8%) of yellowish resin MS:(M+NH4)+451,4 IR (KBr): 1779, 1745, 1680, 1637, 1201, 988 cm-1 Example 17 (a) Benzhydryl (1E,3E) and (1E)3Z)-(2S>3S,5R)-3-(4-cyano- biita-1,3-dienyl)-3-methyl-7-oxo-4-thia-1 -aza-bicyclo- [3.2.0]heptane-2-carboxylate Benzhydryl (1E,3E) and (1E,3Z)-(2S,3S,5R)-3-(4-cyano-buta-1,3- dienyl)-3-methyl-7-oxo-4-thia-1-aza-bieycloE3.2.0]heptane-2- carboxylate is prepared in analogy to Example 4, Method B, from 815 mg (2.14 mmol) of benzhydryl (1E)3E)-(2S,3S,5R)-3-(4- formyl-buta-1,3-dieny|)-3-methyl-7-oxo-4-thia-1-aza-bicyclo [3.2.0]heptane-2-carboxylate. The residual oil is purified over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n- hexane 1:2 as the eluent. Yield: 820 mg (89%) of isomer mixture, E:Z 2:3 Spectroscopic data of the isomer mixture: IR (film): 2215, 1780, 1745, 1202, 989 cm-i MS: (M+NH4+) 448.5 (b) Benzhydryl (1E,3E) and (1E,3Z)-(2S,3S,5R)-3-(4-cyano- buta-1,3-dienyl)-3-methyl-4,4,7-10X0-4-11113-1 -aza- bicyclo[3.2.0]heptane-2-carboxylate 770 mg (1.79 mmol) of benzhydryl (1E,3E) and (lE.SZ)- (2S,3S,5R)-3-(4-cyano-buta-1,3-dienyl)-3-methyl-7-oxo-4- thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are oxidized according to Example 8. The two isomers can be separated by chromatography over silica gel (particle size 0.040-0.063 mm) io with ethyl acetate:n-hexane 9:16 as the eluent. The Z isomer is eluted as the first component. Yield: Z: 430 mg (52%) of Colourless oil E: 280 mg (34%) of colourless foam Spectroscopic data E isomer: MS: (M+NH4)+ 480.5 IR (KBr): 2219, 1800, 1756, 1329, 1191, 994 cm-1 Spectroscopic data Z isomer: MS: (M+NH4)+ 435.3 IR (KBr): 2210, 1800, 1756, 1330, 1192, 993 cm-1 (c) Sodium (1E,3E)-(2S,3S,5R)-3-(4-cyano-buta-1,3-dienyl)- 3- methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 250 mg (0.54 mmol) of benzhydryl(1E,3E)-(2S,3S,5R)-3-(4- cyand-buta-1,3-dienyl)-3*methyl-4,457-trioxo-4-thia-1 -aza- bicydo[3.2.0]heptane-2-carboxylato ars deprotected in analogy to Example 8. Yield: 55 mg (41%) of yellowish lyophilizate IR (KBr): 2221, 1781, 1631, 1397, 1319, 1139, 992 cm-i MS:(M+Na)+341.2 Sodium (1 E,3Z)-(2S,3S,5R)-3-(4-cyano-buta-1,3-dienyl)-3- methy!-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 230 mg (0.49 mmol) of benzhydryl (1E,3E)-(2S,3S,5R)-3-(4- cyano-buta-1,3-dienyl)-3-methyl-4,4,7-trioxo-4-thia-1-aza- bicyclo[3.2.0]heptane-2-carboxylate are deprotected in analogy to Example 8. Yield: 84 mg (58%) of yellowish lyophilizate IR (KBr): 2219, 1780, 1625, 1396, 1316, 1138, 951 cm-i i • a •# 2 0 MS: (M+H)+319.3 Elementary analysis: CiaHnOsSNa (318.279) Example 18 Calc. C 45.28 H 3.48 N 8.80 Found#) C 45.29 H 3.63 N 8.82 #) anhydrous, calculated with 6.93% water (a) Benzhydryl (E/Z)-(2S,3S,5R)-3~methyl-7-oxo-3-[2-oxo-1- (2,2,2-trifluoro-ethyl)-pyrrolidin-3-ylidenmethyl]-4-thia- 1-aza-bicyclo[3.2.0]heptane-2-carboxylate 762 mg (2.0 mmol) of benzhydryl (2S,3R,5R)-3-formyl-3- methyl-7-oxo-4-thid-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are reacted with 1.02 g (2,0 mmol) of rac-[2-oxo-l-(2,2,2- trifluoroethyl)-2-pyrrolidinylHriphenylphosphonium bromide according to Example 12. Chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n- hexane 9:16 as the eluent. Yield: 763 mg (71%) of isomer mixture, E:Z 5:1 Spectroscopic data of the mixture: IR (film): 1782, 1748, 1702, 1664, 1158 cm-1 MS: (M-CPh2) 363 (b) Benzhydryl (E) und (Z)-(2S,3S,5R)-3-methyl-3-[2-oxo-1- (2,2,2-trifluoro-ethyl)-pyrrolidin-3-ylidenemethylJ-4,4,7- trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate 763 mg (1.42 mmol) of benzhydryl (E/Z)-(2S,3S,5R)-3-methyl-7- oxo-3-[2-oxo-1-(2,2,2-trifluoro-ethyl)-pyrrolidin-3-ylidene- 2 o methylH-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate are oxidized according to Example 8. The two isomers can be separ¬ ated by chromatography over silica gel (particle size 0.040- 0.063 mm) with ethyl acetate:n-hexane 1:2 as the eluent. 2 5 Yield: E: 192 mg (24%) of colourless foam Z: 32 mg (4%) of colourless foam Spectroscopic data E isomer: MS: (M+NH4)+ 580.4 IR (KBr): 1801, 1759, 1706, 1667, 1329, 1144 crrH Spectroscopic data Z isomer: MS: (M+NH4)+ 580.4 * a* » • ft IR (KBr): 1798, 1755, 1694, 1327, 1142 cm-1 (c) (E)-(2SI3SI5R)-3-Methyl-3-[2-oxo-1-(2,2,2-trifluoro- ethylj-pyrrolidin-s-ylidenemethyljj-trjoxo-thja-l- aza-bicyclo[3.2.0]heptane-2-carboxylie acid 192 mg (0.34 mmol) of benzhydryl (E)-(2SI3S,5R)-3-methyl-3- [2-OXO-1 -(2,2,2-trif luoro-ethyl)-pyrrolidin-3-ylidenemethyl]- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are deprotected analogously to Example 11. Yield: 78 mg (59%) of colourless crystal powder MS:(M+NH4)+414.4 IR (KBr): 2800(br)I 1790, 1729, 1674, 1646, 1321, 1166 cm-1 Sodium (E)-(2S,3SI5R)-3-methyl-3-[2-oxo-1-(2,2,2-trifluoro- ethyl)-pyrrolidin-3-ylidenemethyl]-4,4,7-trioxo-4'thia-1-aza- bicyclo[3.2.0]heptane-2-carboxylate mg (0.13 mmol) of (EJSS.SS.SRJ-S-methyl-S--oxo-l- (2I2I2-trifluoro-ethyl)-pyrrolidin-3-ylidenemethyl]-4I4,7- trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylic acid are converted into the corresponding sodium salt anatogously to Example 11. Yield: 52 mg (98%) of colourless lyophiJizate IR (KBr): 1780, 1699, 1628, 1478, 1396, 1323, 1140 crrrl Elementary analysis: CiHuNaOsFaSNa (418.318) Calc. C 40.20 H 3.37 N 6.70 3$ Found#) C 39.80 H 3.28 N 6.62 #) anhydrous, calculated with 7.24% water - 52 Example 19 (a) Benzhydryl (E/Z)-(2S,3S,5R)-3-(1-cyclopropyl-2-oxo- pyrrolidin-3-ylicJenemethyl)-3-methyl-7-oxo-4-thia-1 - aza-bicyclo[3.2.0]heptane-2-carboxylate 381 mg (LOmmol) of benzhydryl (2S,3R,5R)-3-formyl-3- methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are reacted with 495 mg (1.1 mmol) of rac-[1-cyclopropyl-2- oxo-3-pyrrolidinyl]-triphenylphosphonium bromide according to Example 18. Chromatography is carried out over silica gel (particle size Q.040-0.063 mm) with ethyl acetate:n-hexane 9:16 as the eluent. Yield: 362 mg (74%) of isomer mixture, E:Z 5:1 Spectroscopic data of the mixture: IR (film): 1780, 1750, 1692, 1661, 1195, 1118 crrr1 MS: (M+H)+ 489,4 Example (a) Benzhydryl (E)-(2S,3S,5R)-3-(3-hydroxy-propen-1-yl).3- methyl-7-oxo-4-thta-1-aza-bicyclo[3.2.Q]heptane-2- carboxylate 5.80 g (14.2 mmol) of benzhydryl (E)-(2S,3S,5R)-3-(2-formyl- vinyl)-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.03heptane-2- carboxylate are dissolved in 240 ml of toluene under argon and cooled to 0oC. Then, 14.2 ml (21.3 mmol) of a 20% diisobutyl- aluminium hydride solution (in toluene) are added dropwise and the cooling bath is removed. The reaction mixture is stirred at room temperature for 6 hours, poured into 150 ml of saturated ammonium chloride solution and extracted three times with 200 ml of methylene chloride each time. The combined organic extracts are washed once with 300 ml of water as well as saturated sodium chloride solution, dried over magnesium sulphate, filtered and freed from solvent on a rotary evaporator. The residual yellow oil is chromatographed over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 9:16 as the eluent. Yield: 1,90 g (32%) of colourless resin IR (film): 3480(br), 1778, 1750, 1202, 1080, 988 cm-i MSr (M+NH4)+ 427.6 (c) Sodium (E)-(2§,3S,5R)-3-(3-hydroxy-propen-1 -yl)-3- methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2- carboxylate :.:": 500 mg (0.95 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl- :'•": 4,4,7-trioxo-3-[3-[(R)- and (S)-tetrahydro-pyran-2-yloxy]- •""• 20 propenyl]-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are :"•— deprotected according to Example 8. Yield: 165 mg (62%) of colourless lyophilizate MS: (M-Na)" 274.3 IR (KBr): 3428, 1780, 1622, 1398, 1311, 1192, 1139, 1082 cm-1 Elementary analysis: CioHNOeSNa (297.257) Calc. C 40.41 H 4.07 N 4.71 Found#) C 40.44 H 4.48 N 4.?9 #) anhydrous, calculated with 8.73% water » • i « ft • Benzhydryl (E)-(2S,3S,5R)-3-methyl-7-oxo-3-[3-[(R)- and (S)- tetrahydro-pyran-2-yloxy]-propenyl]-4-thia-1-aza-bicyclo- [3.2.0]heptane-2-carboxylate 620 mg (1.50mmol) of benzhydryl (E)-{2S,3S,5R)-3-(3-hydroxy- propeny|)-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane- 2-carboxylate are dissolved in 30 ml of methylene chloride and treated with 4.5 mg (0.024 mmol) of p-toluenesulphonic acid monohydrate. Subsequently, 0.25 ml (2.70 mmol) of 3,4-di- hydro-2H-pyran is added and the mixture is stirred for a further 1 hour. The solvent is removed on a rotary evaporator and chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 9:16 as the eluent. Yield: 700 mg (93%) colourless oil, diastereomer mixture (1:1) IR (film): 3031, 1782, 1749, 1257, 1134, 967 crrr1 MS: (M+NH4)+511.6 Benzhydryl (E)-(2S,3S,5R)-3-methyl-4,4,7-trioxo-3-[3-[(R)- und (S)-tetrahydro-pyran-2-yloxy]-propenyl]-4-thia-1-aza-bicyclo- [3»2.0]heptane-2-carboxylate 2 5 585 mg (1.18 mmol) of benzhydryl (E)-(2S,3S,5R)-3-methyl-7- oxo-3-[3-[(R)- and ($)-tetrahydro-pyran-2-yloxy]-propenyl]-4- thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate are oxidized according to Example 8. Chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n- 3 0 hexane 9:16 as the eluent. Yield: 525 mg (84%) of colourless foam, diastereomer mixture (1:1) IR (KBrj: 1800, 1756, 1327, 1189, 1141, 969 cm-i MS: (M+NH4)+ 543.5 Example 21 (a) Benzhydryl (E)-(2S,3S,5R)-3-[3-(2-chloro-acetylamino- carbdnyloxy)-propenyl]-3-methyl-7-oxo-4-thia-1-aza- bicyclo[3.2.0]heptane-2-carboxylate 300 mg (0.73 mmol) of benzhydryl (E)-(2S,3S)5R)-3-(3-hydroxy- propenyl)-3-methyl-7-oxo-4-thia-1-aza-bicyclQ[3.2.0]heptane- 2-earboxylate are dissolved in 10 ml of tetrahydrofuran under i o argon and treated with 90 jil (1.05 mmol) of chloroacetyl isocyanate. The mixture is stirred for 3 hours, evaporated and chromatography is carried out over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 9:16 as the eluent. Yield: 300 mg (77%) of colourless foam IR (KBr): 3300(br), 1779, 1753, 1730, 1495, 1203 cm-i MS: (M+NH4)+ 546.4 (b) Benzhydryl (E)-(2S,3S,5R)-3-[3-(2-chloro-acetylamino- carbonyloxyJ-propenyll-S-methyMJ-trioxo-thia-l- aza-bicyclo[3.2.0]heptane-2-carboxylate 295 mg (0.57 mmol) of benzhydryl (E)-(2S,3S,5RJ-3-[3-(2- chloro-acetylaminocarbonyloxy)-propenyl]-3-methyr7-oxo-4- thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate are oxidized analogously to Example 8. Chromatography is carried out over Silica gel (particle size 0.040-a.G63 mtD) with ethyl acetate:n- hexane 9:16 as the eluent. Yield: 216 mg (68%) of colourless foam IR (KBr): 3413(br), 1798, 1758, 1730, 1705, 1326, 1198, 991 cm*i MS: (M+NH4)+ S78.4 (c) Sodium (E)-(2S,3S,5R)-3-{3-(2-chloro-acetylamino- carbonyloxyJ-propenylJ-a-methylJ-trioxo-A-thia-l- aza-bicyclo[3.2.0]heptane-2-carboxylate 195 mg (0.35 mmol) of benzhydryl (E)-(2S)3S,5R)-3-[3-(2- chloro-acetylaminocarbonyloxy)-propenyl]-3-methyl-4,4,7- tr4oxo-4-thia-1 -a2a-bicy6lo[3.2.0]heptane-2-carboxylate are deprotected in analogy to Example 8 and converted into the corresponding sodium salt. Yield; 60 mg (49%) of colourless lyophilizate MS: (M-COCH2CI-Na)- 317.3 IR (KBr): 3435, 1781, 1721, 1622, 1533, 1396, 1314, 1192, 1139 cm-1 1H-NMR (250MHz, D20):S[ppm] = 1.61(5,31-1), 3.42(dd,1H,J=16Hz, 1.6Hz, 6-H), 3.69(dd, 1H, J=16Hz, 4.0Hz, 6-H), 4.43(s)2H,CH2CI), 2 0 4.49(s,1H,2-H), 4,84(d,2H,J-4.4Hz,CH20)I 5.08(64JSHz, 4.0Hz, 5-H), 6.08(d(br),1H,J=16Hz,=CH), 6.22(dt,1H,J=16Hz, 4.4Hz, =CH) Example 22 2 5 Benzhydryl (E)-(2S,3S,5R)-3-(carbamoyioxy-propenyl)-3-methyl- 4,4t7-trioxo-4-thia-1-aza-b1cycloI3.2.0]heptane-2-carboxylate 450 mg (0.80 mmol) of benzhydryl (EH2S,3S,5)-3-[3-(2- chloro-acetylaminocarbonyloxy)-propenyl]-3-methyl-4,4,7- 3 a trioxo-4-thia-1 -aza-bicycloi3.2.0]heptane-2-carboxylate ars dissolved in 5 ml of tetrahydrofuran under argon and treated with 1.7 ml of methanol. 135 mg (1.61 mmol) of sodium hydrogen carbonate in 2.8 ml of water are added to this solution. After completion of the reaction (tic control) the solvent mixture 3S is removed on a rotary evaporator, the residual yellow oil is taken up in 15 ml of ethyl acetate as well as 15 ml of saturated sodium chloride solution, shaken and the phases are separated. The aqueoys phase is back-extracted twice with 1Sml of ethyl • • f acetate each time and the combined organic extracts are washed once with 15 ml of saturated sodium chloride solution. They are dried over magnesium sulphate, concentrated on a rotary evapor¬ ator and the residual oil is chromatographed over silica gel (particle size 0.040-0.063 mm) with ethyl acetate:n-hexane 2:1 as the eluent. Yield: 200 mg (78%) of colourless foam IR (KBr): 3481, 1799, 1749, 1731, 1601, 1329, 1191, 996 citH MS: (M+NH4)+ 484 (c) Sodium (E)-(2sS,3SI5R)-3-(carbamoyloxy-propeny1)-3- methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2- carboxylate 190 mg (0.60 mmol) of benzhydryl (E)-(2S,3S,5R)-3-(carbamoyl' oxypitopenyl)-3-methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo- •««• 20 E3.2.0]h6ptane-2-carboxylate are deprotected in analogy to "•*** Example 8. Yield: 82 mg (62%) of colourless lyophilizate 'H-NMR (250MHz, D2O}: S[ppm] = 1.61(s,3H), 3.42(dd,1H,J=17Hz, 1.6Hz,6-R)t 3.69(dd,lH,J-17Hz,4Hz,6H), 4.48(S,1H,2-H), 4.70 (d,2H»J-4.6Hz,CH2), 5.08(dd,1H,J=4Hz, 1.6Hz,5-H), 5.97 (ds1H,a*16Hz,-CH), 6.19(dt,lH,J-16Hz, 4.6Hz,-CH). 3 0 Eacample 3 (a) (2S,3S,SRM-{3-(2-Benzhydryloxycarbonyl-3-methyl-7- oxo-4-thia-1-aza-bicyclo[3.2»0]heptan-3-yl)-allyl]- pyridinium triftuormethanesulphonate 410 mg (I.Ommol) of benfftyfryl (E)-(2S,3S,5R)-3-(3-hydroxy' pr0penyi)-3-m®thyl-7-oxo-4-thia-1-a2a-bicyclo[3.2.O]heptane- 2-car&oxyfate are dissolved in 6 ml of methylene chloride, cooled to -40OC and treated with 2501 (1.5 mmol) of trifluoro- methanesulphonic anhydride. After 5 minutes 200 nl (2.50 mmol) of pyridine are added, the mixture is stirred at the same temperature for a further hour and subsequently the cooling bath is removed. The solvent is removed on a rotary evaporator at room temperature, the reaction mixture is taken up in 20 ml of methylene chloride and washed twice with 10 ml of saturated sodium chloride solution each time. Drying over magnesium sulphate, filtration and concentration on a rotary evaporator are io carried out. The residual red resin is oxidized without further purification. Yield: 600 mg (97%) of red resin MS: (M+)471.6 IR (KBr): 1777, 1743, 1630, 1160, 987 cm-1 (b) (2S,3S,5R)-1 -[3-{2-Benzhydryloxycarbonyl-3-methyl- 4,4,7-trioxo-4-thia-1-aza-bicyclo[3,2.0]heptan-3-yl)- airylj-pyridinium trifluoromethanesulphonate 600 mg (0.97 mmol) of (2S,3S,5R)-1-[3-(2-benzhydryloxy- carbonyl-3-methyl-7-oxo-4-thia-1-aza-bicyclo[3.2.03heptan-3- yl)-allyl]-pyridinium trifluoromethanesulphonate are oxidized in analogy to Example 8. Yield: 440 mg (70%) of green resin MS: (M+) 503.3 IR (KBr): 1797, 1753, 1632, 1167 cm-1 (E)-(2S53S,5R)-3*Methyl-4,4,7-tri0xo-3-(3-pyridrn-1-ylio- propenyl)-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate A Solution of 440 mg (0.67 mmol) of (2S,3S,5R)-1-t3-(2- benzhydrylOxycarbonyl-3-methyl-4»4,7-trioxo-4-tWa-1-aza- bicyclo[3.2.0]heptan-3-yl)-allyl]-pyridinium trifluoromethane- sglphonate in 3 ml of m-cresol is stirred at 50OC for 1.5 hours. The mixture is diluted with 10 ml of isobutyl methyl ketone at room temperature and extracted three times with 8 ml of water each time. The combined aqueous extracts are washed twice with ml of isobutyl methyl ketone each time, filtered over a paper filter and lyophilized. The brown lyophilizate is subsequently chromatographed over polymeric hydrophobic gel with water as the eluent. Yield: 125 mg (55%) of beige lyophilizate IR (KBr): 1780, 1625, 1485, 1372, 1312, 980 crrr1 MS: M+H+337.4 k « Claimo The claims defining tho invention are as follows: 1. 2p-Alkenyl-penam derivatives of the general formula ii R1 COOR3 wherein one of R1 and R2 signifies -COR4, -CN, -CH2R5, halogen, -CH=CHR6 or Q arid the other signifies hydrogen or lower alkyl or both 1 0 together signify a y-lactam ring, R3 signifies hydrogen, lower alkyl, aryl-alkyl, allyl or a residue which is cleavable in vivo, R4 signifies hydrogen, lower alkyl, lower alkoxy, benzyloxy, amino, lower alkylamino or lower alkyl-lower alkoxyamino, R5 signifies hydroxy, -OCONHR7, -OCONH2 or a five- or six- membered hetero-aromatic ring which contains N,S and/or O and which is linked via a nitrogen atom, R6 signifies -CN or CHO, R7 signifies -COCH2CI, Q signifies a five- or six-membered hetero-aromatic ring which contains N, S and/or O and n signifies 0, 1 or 2, as well as pharmaceuticafly compatible salts of these compounds. 2 5 2. Compounds according to claim 1r wherein one of R1 and R2 signifies -COR4, -CN or -CH2OR5 and the other signifies hydrogen or lower alkyl, R3 signifies hydrogen, lower alkyl, aryl-alkyl, allyl or a residue which is cleavable in vivo, R4 signifies hydrogen, Idwer alkyl, lower alkoxy, benzyloxy, amino or lower alkylamino, Rs signifies hydroxy or -CONN2, R§ signifies lower alkyl and ft signifies 0, t of 2.