PURPOSE: To obtain optically active 2-alkoxycarbonyl-2-cycloalkene derivatives useful as a starting substance for medicines and agricultural chemicals.

CONSTITUTION: The optically active 2-alkoxycarbonyl-1-acyloxy-2-cycloalkene of formula I (* indicates asymmetric carbon; R1 and R2 are alkyl; n is 1 or 2), e.g. (+)-2-ethoxycarbonyl-1-acetyloxy-2-cyclopentene and the optically active 2-alkoxycarbonyl-2-cycloalken-1-ol of formula II, e.g. (-)-2-ethoxycarbonyl-2- cyclopenen-1-ol. These compounds of formulas I and II are obtained by subjecting a dialdehyde derivative of formula III to the Wittig-Horner reaction, providing a racemic-2-alkoxycarbonyl-2-cycloalken-1-ol of formula IV and then carrying out the ester interchange reaction of the resultant compound with an acylating agent in the presence of a lipase, preferably the lipase derived from a bacterium of the genus Pseudomonas.