Investigation of the regioselectivity of some esterifications involving methyl 4,6-O-benzylidene D-pyranosides and Pseudomonas fluorescens lipase

Abstract

Using Pseudomonas fluorescens lipase in vinyl acetate, the methyl 4,6-O-benzylidene-α-D-pyranosides 1 and 6–8 have been esterified with very high selectivity to afford the C-2 acetates 3 and 10–12, respectively. In contrast the methyl 4,6-O-benzylidene-β-D-pyranosides 2 and 9 are acetylated under the same conditions to give the C-3 esters 5 and 13 with high/exquisite regioselectivity.