Enzymatic synthesis of some Wax‐esters

The Mucor miehei lipase, immobilized on a macroporous anion‐exchange resin (Lipozyme TM), was used to catalyze esterification and interesterification for the synthesis of wax‐esters. The first series of saturated esters, from 20 to 28 carbon atoms, were obtained with more than 80% yield. These esters are liquid up to 24 carbon atoms. Monounsaturated wax‐esters from 28 to 36 carbon atoms, were synthesized with yields greater than 70%. With few exceptions all these compounds are liquid up to 34 carbon atoms. Attempts of alcoholysis involving the ricinoleyl chain, revealed the remarkable selectivity of Lipozyme. Primary esters were found to be the sole reaction products (yields from 79 to 81,5%). It was possible to prepare diesters from octanediol and suberic acid with good yields (84–92%). Unfortunately yields were moderate in the synthesis of monoesters. 1,2‐alkanediol monolaurates were easily and selectively synthesized, but with a low yield. A fair amount of secondary ester was found besides the expected primary ester. A mechanism involving an equilibrium between both esters via a cyclic intermediate accounted for the acyl migration.