Synthesis of Glycosyl Acceptors by Regioselective Benzylations of a 2-Deoxy-2-phthalimido-D-glucoside.

Abstract

The direct regioselective benzylation of p-methoxyphenyl 2-deoxy-2-phthalimido-β-D-glucopyranoside (1) with benzyl bromide under basic conditions gives 4,6-di-O-benzyl (2a), 4-O-benzyl (3a) and 6-O -benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside 4a. When the benzylation was performed in the presence of di-n-butyltin oxide, p-methoxyphenyl 4,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside 5 was obtained in high yield. This constitutes a new and efficient one-pot procedure for the synthesis of the glycosyl acceptor 5.