Lipase-Catalyzed Enantioselective Copolymerization of Substituted Lactones to Optically Active Polyesters
journal contributionposted on 28.11.2000, 00:00 by Hirofumi Kikuchi, Hiroshi Uyama, Shiro Kobayashi
Enantioselective copolymerization of racemic substituted lactones with achiral lactones has been examined by using Candida antarctica lipase as catalyst. In the copolymerization of racemic β-butyrolactone with 12-dodecanolide, the (S)-isomer was preferentially reacted to give the (S)-enriched optically active copolymer with enantiomeric excess of β-butyrolactone unit = 69%, which is much larger than that of the homopolymerization under similar reaction conditions. The absolute configuration of β-butyrolactone unit in the copolymer was confirmed by the acid-catalyzed methanolysis to methyl 3-hydroxybutyrate. δ-Caprolactone was also enantioselectively copolymerized by the lipase catalyst to give the optically active polyester. The highest ee value (76%) was achieved by the copolymerization of δ-caprolactone and 12-dodecanolide in diisopropyl ether.