Chemoenzymatic synthesis of optically active 4-methyl-tetrahydro-5-oxo-2-furancarboxylic acids and esters

Enantiomerically pure 4-methyl-tetrahydro-5-oxo-2-furancarboxylic acids and esters are prepared by enzymatic resolution of the chiral racemic esters. Their stereochemistry as well as their absolute configurations have been es tablished by chemical correlation. The influence of the alkoxycarbonyl grou p at C-2 and that of the methyl group at C-4 on the sign of the Cotton effe ct in their CD spectra have been investigated. Formation of enantiomericall y pure hydroxydiesters, precursors of the above-mentioned gamma-lactones, b y baker's yeast reduction of the corresponding ketodiesters was unsatisfact ory. (C) 2000 Elsevier Science Ltd. All rights reserved.