Enzymatic Syntheses of Chiral Building Blocks from Racemates: Preparation of (1<i>R</i>,3<i>R</i>)‐Chrysanthemic, ‐Permethrinic and ‐Caronic Acids from Racemic, Diastereomeric Mixtures

Abstract

The use of enantioselectivley reactive enzymes on the laboratory scale offers great advantages. With procine liver esterase, for example, chrysanthemic acid (1R,3R)-1 can be prepared from a mixture of the four esters with (1S,3R)-, (1R,3S)- (1S,3S)-, and (1R,3R)-configuration. Diastereoselective hydrolysis of the mixture affords the trans-acids (1S,3S)-1 and (1R,3R)-1. Enantioselective hydrolysis of the trans-ester leads to (1R,3R)-1, which is of interest in connection with the pyrethroid insecticides.