Synthesis and biological resolution of condensed bicyclic isoparaconic acid derivatives

Abstract

Kinetic resolution of chiral racemic (1R*,3aS*,7aS*)-hexahydro-2-oxobenzofuran-3-ylacetic acid ethyl ester was achieved by means of immobilized Lipozyme^®. At low conversion values, the (−)-acid was isolated with 84% ee, while at high conversion values the (+)-ester was obtained with 98% ee. Their configurations were determined by transformation of the acid into the corresponding α-methylene derivative of known absolute configuration.