Process of producing optically active cephalosporin analogs by enzyme selective deacylation

A process for producing optically active compounds represented by the formula:

• ##STR22## wherein R.sub.1 represents a hydrogen, a lower alkyl group or a lower acyl group and R.sub.2 represents a hydrogen or a protective group of carboxylic acid, which comprises reacting a compound represented by the formula ##STR23## wherein R represents a substituted or unsubstituted unsaturated six-membered carbocycle or a substituted or unsubstituted heterocycle, X represents a hydrogen, an amino group, a hydroxy group or a lower alkyl group, R.sub.1 and R.sub.2 have the same significance as defined above, and the hydrogens at the 6- and 7-positions have cis configuration with an enzyme capable of selective optical deacylation and thereafter recovering said optically active compounds.