Abstract The syntheses of the unprotected,(Z)-configurated hexon-and pentonhydroximo- lactones 2a–12a by oxidation of D-glucose, cellobiose, D-galactose, D-mannose, 2- acetamido-2-deoxy-D-glucose, D-ribose, and D-arabinose oxime with MnO 2, Hg (OAc) 2, or O 2 in the presence of Cu 2 Cl 2/pyridine are described. An (E/Z)-pair of protected hydroximo- lactones 14 and 15 was obtained by oxidation of the diisopropylidene-D-mannose oxime ...