Lipase-catalysed esterification in supercritical carbon dioxide and in hexane

Isoamyl acetate was synthesised in high yields (>90%) via lipase catalysed acylation of the corresponding alcohol by ammonium acetate in supercritical carbon dioxide (SCCD) and by acetic acid in hexane. The esterification rate was higher in hexane. The product yield depended sharply on the reagent concentrations in hexane whereas it was nearly independent on the pressure and temperature of the SCCD.