Synthesis of 1-deoxyhept-2-ulosyl-glycono-1,5-lactone utilizing α-selective O-glycosidation of 2,6-anhydro-1-deoxy-D-hept-1-enitols

Abstract A series of 1-deoxy-heptulo-2-pyranosyl-glycono-1,5-lactones were synthesized utilizing completely α-selective O-glycosidation of heptenitols. Anomeric configuration of the products was confirmed by 3 J C,H coupling measurement and X-ray crystal structural analysis. The benzyl-protected ketosyl saccharides were partly unstable, and glycosidic linkage was prone to cleave under the usual debenzylation conditions. To prevent this, we surveyed various additives for the Pd-catalyzed hydrogenation reaction and found that basic alumina was the most effective.