Enzymic acylation of methyl D- and L-glycopyranosides: Influence of the 3-hydroxyl group

Porcine pancreatic (PPL), Candida cylindracea (CCL) and Pseudomonas cepacia (LPS) lipases, suspended in organic solvents, were used to regioselectively acylate methyl 6-O-butyryl-\u3b1-D- and L-allopyranosides and methyl 6-O-butyryl-3-deoxy-\u3b1-D- and L-ribo-hexopyranosides. Both the D- and the L-3-deoxy sugars showed a complete regioselectivity, while the reactions of the allosides proved to be less regioselective. This indicates that the presence of the hydroxyl group at C-3 is an unfavourable factor for the action of the lipases