OXIDATION-PRODUCTS OF C-4 AND C-7 HYDROXYLS IN THE METHYL ALPHA-GLYCOSIDE DERIVATIVES OF KDN

A regioselective protection of hydroxyl groups in the methyl ester-met hyl alpha-glycoside derivative of KDN was demonstrated. Isopropylidena tion of methyl (methyl -alpha-D-glycero-D-galacto-2-nonulopyranosid)on ate (1) gave mono- (8,9) and di- (5,7:8,9) O-isopropylidene derivative s. Benzoylation of methyl (methyl 3-deoxy-8, 9-O-isopropylidene-alpha- D-glycero-D-galacto-2 -nonulopyranosid)onate (7) gave di- (4,5) and tr i- (4,5,7) O-benzoates. Through these reactions, it was found that the reactivity of the hydroxyl groups was different from that of methyl b eta-glycoside of KDN. Oxidation products of C-4 and C-7 hydroxyl group s (6 and 11) were synthesized from these compounds.