Abstract The synthesis of 5′-O-β-d-glucopyranosyl and 5′-O-β-d-galactopyranosyl derivatives (13 and 15, respectively) of the antiviral agent ribavirin are descrobed. Direct glycosylation of 2′, 3′-O-isopropylideneribavirin with either tetra-O-acetyl-α-d- glucopyranosyl bromide (4) or tetra-O-acetyl-α-d-galactopyranosyl bromide (8) under Koenigs-Knorr conditions (ie., silver carbonate, silver perchlorate, and Drierite in ...