Zinc acetate catalyzed stereoselective 1,2 trans glycosylation using glycosyl chlorides

We report the strategy for the stereoselective synthesis of 1,2-trans glycosides in the absence of NGP (neighboring group participation). Present protocol for the selective glycosylation mainly rely on catalyst control rather than protecting group selection. Using this protocol, several glycosides were prepared. Cost effective zinc acetate was found to be the best catalyst that provided desired 1,2-trans glycosides from glucose and mannose derived glycosyl halides at room temperature unlike traditional cryogenic conditions.