Optimization of Chemo‐Enzymatic Epoxidation of Cyclohexene Mediated by Lipases

Abstract

This work describes the lipase‐mediated epoxidation of cyclohexene. Lipases were used to generate peroxyoctanoic acid directly from octanoic acid and hydrogen peroxide and applied in situ to obtain cyclohexene oxide. Various parameters, which could affect this reaction, were studied such as lipases from different sources, organic solvents, temperature and acyl donor concentrations. Highest conversions to cyclohexene epoxide were achieved using a two‐phase system of toluene or xylene/water with ROL (Amano F‐Ap15 free Rhizopus orizae lipase) (84 and 80%) or CALB (Novozymes 435®‐immobilized Candida antarctica lipase type B) (>9 and 84%) as biocatalysts. Using PSL (Amano PS‐free Pseudomonas sp) the conversions were in the range of 12–53%, but an improvement was obtained by the use of the ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate (20 to 41% in water/methyl dichloride).

Keywords:

• Two‐phase system
• epoxidation
• lipases

Acknowledgments

The authors are grateful to Universidade Federal de Santa Catarina (UFSC), Conselho Nacional de Pesquisa e Desenvolvimento (CNPQ) for financial support and scholarships (M.A.M., T.B.B., and M.G.N.) and Amano Pharmaceutical Co. and Novozymes Inc. for the donation of lipases. J. Dupont (IQ‐UFRGS) is also acknowledged for his generous gift of ionic liquid.