RECENT ASPECTS OF THE CHEMISTRY OF DISACCHARIDES

Abstract

Our interest has focussed on stereoselective chemical manipulations of readily available disaccharides either by replacement of specific hydroxyl groups, for example, by halogenation, or by selective esterification of the more reactive hydroxyl groups. In the latter, the unreacted hydroxyl groups are subsequently modified. Another approach has been to prepare selected sulphonate esters by stereospecific reactions followed by the introduction of new substituents by nucleophilic displacement of the sulphonyloxy groups. The observed stereoselectivity in the latter nucleophilic substitutions and also that encountered in the halogenations, using either sulphuryl chloride-pyridine or mesyl chloride-N,N-dimethylformamide, was in general accordance with the empirical bimolecular, nucleophilic, transition state theory.