Enzymatic Transesterification of Sugars in Anhydrous Pyridine

Enzymatic transesterification of sucrose, α-methyl glucopyranoside and octyl-D-glucopyranoside with tributyrin, vinyl octanoate and vinyl laurate was carried out in nearly anhydrous pyridine using the bacterial protease, alcalase. The enzyme monoacylated both the α and β anomers of octyl-D-glucopyranoside. In addition to the preferential acylation of the primary hydroxyl groups of the sugars, the enzyme also acylated the secondary hydroxyl groups in lower quantities. The generated sugar mono-, di- and triesters were purified by flash column chromatography and the positions of acylation were assigned by 13C NMR.