A Study on the Process of Lipase-catalyzed Synthesis of α-pinene Oxide in Organic Solvents

摘要

The synthesis of α-pinene oxide was studied in a three-phase system where immobilized Candida antarctica lipase B (Novozyme 435) was used to catalyze the formation of peroxyoctanoic acid from the parent car-boxylic acid and hydrogen peroxide in toluene. The peroxycarboxylic acid formed was then used in situ for the oxidation of α-pinene to the corresponding epoxide. When hydrogen peroxide was added in the reaction mixture gradually over 6 h, conversions increased up to 31.6%. Initial rates of α-pinene oxidation increased from 85 to 708 mmol L~(-1) h~(-1) when the amount of H_2O_2 increased from 5 to 60 mmol. When the lipase was exposed to 75 mmol H_2O_2 for 0.5 h before its addition in the reaction mixture, its activity decreased to about 50%. The reusability of lipase was studied in five reaction cycles and was found to depend on the concentration of the hydrogen peroxide used.