Nucleophilic replacement reactions of sulphonate esters. Part V. The synthesis of derivatives of 2,3,4,6-tetra-amino-2,3,4,6-tetradeoxy-D-glucose

Abstract

The synthesis of methyl 2-acetamido(or benzamido)-3,4,6-triazido-2,3,4,6-tetradeoxy-α-D-glucopyranoside has been investigated by a number of routes involving displacement reactions of sulphonate esters, and its reduction to derivatives of 2,3,4,6-tetra-amino-2,3,4,6-tetradeoxy-D-glucose has been accomplished. During the course of this work it has been found that attempted oxidation of a hydroxy-group with dimethyl sulphoxide–acetic anhydride leads instead to preferential acetylation when it is adjacent to either a cis-acylamido- or a trans-equatorial acylamido-substituent. It has also been established that replacement of a sulphonyloxy-group attached to a pyranoside ring is impeded by the presence of a vicinal axial electronegative substituent, and this has been interpreted in terms of a polar field effect.