CONVENIENT METHODS FOR THE SYNTHESIS OF BETA-C-GLYCOSYL ALDEHYDES

Two methods for the stereoselective beta-formylation at the anomeric c arbon of three saccharides are described. In Method A the formyl group is introduced on the starting lactone by a dithiane ring which, after stereospecific reductive dehydroxylation, is hydrolysed to generate t he beta-glycosyl aldehyde. In Method B the aldehyde is prepared by int roduction of phenylacetylene followed by stereospecific reductive dehy droxylation, partial hydrogenation and subsequent ozonolysis.