PROCESS FOR PREPARING OPTICALLY ACTIVE ISOMERS OF 2-HALO-2-FLUOROCYCLOPROPANECARBOXYLIC ACIDS

摘要

A process for preparing a particular optically active isomer of a 2-halo-2-fluorocyclopropanecarboxylic acid from a 2-halo-2-fluorocyclopropanecarboxylic ester comprising a mixture of optically active isomers. The process is characterized by asymmetrically hydrolyzing a 2-halo-2-fluorocyclopropanecarboxylic ester represented by general formula (1), (wherein X represents a chlorine, bromine, or iodine atom; R represents a lower alkyl group; and * represents an asymmetric carbon atom), using an esterase having a capability of asymmetrically hydrolyzing the ester.