A study of the enantiopreference of Lipase PS (Pseudomonas cepacia) towards diastereomeric dihydro-5-alkyl-4-hydroxymethyl-2(3H)-furanones

Lipase PS acetylation of diastereomeric dihydro-4-hydroxymethyl-2(3H)-furanones bearing a methyl or a pentyl group at C-5 have been studied. Higher enantioselectivities were found for the cis-isomers with respect to the trans-isomers. They were also higher for the systems bearing the longer alkyl chain. Lipase PS-catalyzed hydrolyses of racemic acetates were found to follow the same trend, although the efficiency of the enzyme was lower than in the acetylation reactions. These results were supported by molecular modelling studies that correctly predicted the maximum stereoselectivity for the cis-isomer of 5-pentyl substituted lactones both in acetylation and in hydrolysis reactions