Oxidation Products of C-4 and C-7 Hydroxyls in the Methyl α-Glycoside Derivatives of KDN 1

Abstract A regioselective protection of hydroxyl groups in the methyl ester-methyl α-glycoside derivative of KDN was demonstrated. Isopropylidenation of methyl (methyl 3-deoxy-α-D-glycero-D-galacto-2-nonulopyranosid)onate (1) gave mono- (8,9) and di- (5,7:8,9) O-isopropylidene derivatives. Benzoylation of methyl (methyl 3-deoxy-8, 9-O-isopropylidene-α-D-glycero-D-galacto-2-nonulopyranosid)onate (7) gave di- (4,5) and tri- (4,5,7) O-benzoates. Through these reactions, it was found that the reactivity of the hydroxyl groups was different from that of methyl β-glycoside of KDN. Oxidation products of C-4 and C-7 hydroxyl groups (6 and 11) were synthesized from these compounds. 1. Presented at the XVIIIth International Carbohydrate Symposium, Milan, Italy, July 21-26, 1996.