gamma-Acyloxy-epsilon-Caprolactones: Synthesis, Ring-Opening Polymerization vs. Rearrangement by Means of Chemical and Enzymatic Catalysis
2008 (English)In: Macromolecular Symposia, ISSN 1022-1360, E-ISSN 1521-3900, Vol. 272, 28-38 p.Article in journal (Refereed) Published
gamma-Acyloxy-epsilon-caprolactones (3a-d) were prepared in two steps starting from 4-hydroxy-cyclohexanone (1). in the first step acylation of the hydroxyl group occurs and in the second step ring enlargement by Baeyer-Villiger oxidation. if this order of reaction is inverted rearrangement occurs in the Baeyer-Villiger oxidation Of 4-hydroxy-cyclohexanone leading to gamma-hydroxyethyl-gamma-butyrolactone. Using the first procedure gamma-acetyloxy- (33), gamma-benzoyloxy-(3B), gamma-acryloyloxy-(3c), and gamma-methacryloyloxy-epsilon-caprolactone (3d) were prepared. These monomers and for comparison reasons epsilon-caprolactone and gamma-methyl-epsilon-caprolactone were polymerized by means of chemical and enzymatic catalysis. The results were different depending on the monomer structure and catalyst used. in the presence of a chemical catalyst, all the monomers, except gamma-acetyloxy-epsilon-caprolactone, undergo controlled ring-opening polymerization. gamma-Acetyloxy-epsilon-caprolactone (3a), however, rearranges to a large extent under polymerization conditions to give gamma-acetyloxyethyl-gamma-butyrolactone (6a). in the presence of an enzyme (Novozyme 435, Lipase B from Candida antarctica (CALB) immobilized on a macroporous resin) all gamma-acyloxy-epsilon-caprolactones partly rearrange to result the corresponding gamma-acyloxy-gamma-butyrolactones, while epsilon-caproiactone and gamma-methyl-epsilon-caprolactone yield the corresponding polymers, the latter even in a stereoselective manner as reported earlier in the literature. A molecular dynamic study was performed with 3a and 3b as substrates to gain information on the substrate recognition displayed by CALB. A mechanism for the chemically and enzymatically catalyzed reactions of gamma-acyloxy-epsilon-caprolactones is proposed.
Place, publisher, year, edition, pages
2008. Vol. 272, 28-38 p.
enzyme and chemical catalysis, ring-opening polymerization, gamma-Acyloxy-epsilon-caprolactones
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-24968DOI: 10.1002/masy.200851203ISI: 000261674400003ScopusID: 2-s2.0-55849127376OAI: oai:DiVA.org:kth-24968DiVA: diva2:354711
International Conference on (Bio)degradable Polymers from Renewable Resources Vienna, AUSTRIA, NOV 18-21, 2007
QC 20101004 (International Conference on (Bio)degradable Polymers from Renewable Resources Vienna, AUSTRIA, NOV 18-21, 2007)2010-10-042010-10-042014-10-21Bibliographically approved