Lipase-catalyzed transesterification of primary terpene alcohols with vinyl esters in organic media

Several microbial lipases were screened for their ability to catalyze the synthesis of citronellyl and geranyl esters in organic media using vinyl esters as acylating agents. Based on the results, an immobilized lipase, SP 435 from Candida antarctica was chosen for the study of the effect of reaction parameters on terpenyl acetate synthesis. This enzyme at 10% (w/w reactants) gave yields of 97.7 and 98.6% for geranyl and citronellyl acetate, respectively. Time course studies showed optimum yields could be obtained after 8 and 16 h incubation, respectively. For both terpenyl acetates, solvents with log P > 3.2 gave highest yields and a temperature range between 30-50 degrees C seemed suitable for the synthesis of these primary terpenyl acetates. With some solvents, up to 100% yield of geranyl acetate was obtained. In these solvents, SP 435 showed preference for geraniol. (C) 1998 Elsevier Science B.V.