Enzymatic polyesterification in organic media. II. Enzyme‐catalyzed synthesis of lateral‐substituted aliphatic polyesters and copolyesters

Abstract

AbstractEnzymatic polymerization of hydroxyesters in organic media has been the subject of a previous and ongoing research in our laboratory. As part of that study, four ϵ‐substituted‐ϵ‐hydroxyesters were synthesized, and then polymerized using crude porcine pancreatic lipase (PPL) in n‐hexane. These lateral‐substituted hydroxyesters polymerized enantioselectively to produce optically active oligomers and a resolved optically active unreacted monomer. It was found that with increasing bulkiness of the lateral substituent, in the order Me >Et >Ph, the enzymatic reaction becomes slower, yet the enantioselectivity is higher. The lateral‐substituted hydroxyesters were also copolymerized enzymatically with the more reactive linear methyl ϵ‐hydroxyhexanoate. Optically active copolymers were obtained, higher in molecular weight than the analogous homopolymers. © 1993 John Wiley & Sons, Inc.