Enantiospecific Synthesis of Pseudoacarviosin as a Potential Antidiabetic Agent

A pseudo-1,4′-<i>N</i>-linked disaccharide, pseudoacarviosin <b>5</b>, was constructed via a key palladium-catalyzed coupling reaction of pseudoglycosyl chloride <b>8</b> (prepared from d-glucose via a novel direct intramolecular aldol addition in 12 steps) and pseudo-4-amino-4,6-dideoxy-α-d-glucose <b>9</b> (prepared from l-arabinose via an unusual <i>trans</i>-fused isoxazolidine-selective intramolecular nitrone−alkene cycloaddition in 11 steps). Pseudoacarviosin <b>5</b> 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.