OPTICALLY ACTIVE 'alpha'-SUBSTITUTED CARBOXYLIC ACID DERIVATIVE AND PROCESS FOR PRODUCING THE SAME

An optically active 'alpha'-substituted carboxylic acid derivative represented by general formula (I) wherein R1 represents hydroxy, -C(=CH2)-COOR3 or -CH(CH3)-COOR3; R2 represents methyl or chloro; R3 represents hydrogen or C1-C6 alkyl; n represents an integer of 1 or 2; and the asterisk represents asymmetric carbon, provided when R1 represents hydroxy, R2 represents chloro; and a process for producing the derivative or an enantiomer thereof by using a culture of a microorganism capable of asymmetrically hydrolyzing an ester linkage or a cell thereof which may have been suitably treated. These compounds are useful as the starting material of various liquid crystals and as an intermediate for synthesizing optically active drugs and pesticides.