Enantiospecific synthesis of pseudoacarviosin as a potential antidiabetic agent.

A pseudo-1,4′-N-linked disaccharide, pseudoacarviosin 5, was constructed via a key palladium-catalyzed coupling reaction of pseudoglycosyl chloride 8 (prepared from d-glucose via a novel direct intramolecular aldol addition in 12 steps) and pseudo-4-amino-4,6-dideoxy-α-d-glucose 9 (prepared from l-arabinose via an unusual trans-fused isoxazolidine-selective intramolecular nitrone−alkene cycloaddition in 11 steps). Pseudoacarviosin 5 has been shown to be a potent inhibitor of α-glucosidases, particularly the intestinal mucosal enzymes sucrase and glucoamylase of relevance to blood glucose control.