Synthesis of geranyl acetate by transesterification of geraniol with ethyl acetate over Candida antarctica lipase as catalyst in solvent‐free system

Abstract

Increasing environmental awareness has forced researchers to minimize the use of organic solvents in chemical synthesis. Modern biocatalysis is a way to develop clean catalytic technologies. A process operating in solvent-free condition using reusable biocatalyst, will be useful for the fragrance and flavour industry, which requires stringent specifications on impurities. A direct transesterification reaction of geraniol with ethyl acetate was carried out to produce geranyl acetate in a batch reactor using different immobilized enzymes. Among these, Novozyme 435 was the best catalyst for the synthesis of geranyl acetate in a solvent-free medium. Parametric studies were conducted to optimize the conversion and yield. Overall, 83% conversion of geraniol with 100% selectivity to geranyl acetate was obtained at a mole ratio of 1:7 of geraniol to ethyl acetate, using 12.7 g L−1 Novozyme 435 at 60 °C for 2 h. At higher concentrations of acyl donor, it was noticed that the conversion of geranyl acetate was increased. The Lineweaver–Burk plots suggested a ternary complex with inhibition by ethyl acetate. The process is green, clean, and useful to the perfume and flavour industries.