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

Abstract

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 carboxylic 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 H₂O₂ increased from 5 to 60 mmol. When the lipase was exposed to 75 mmol H₂O₂ 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.

• α-pinene
• Epoxide
• Candida antarctica lipase
• Hydrogen peroxide
• Peroxycarboxylic acid