Aldonhydroximo‐lactones. Preparation and Determination of Configuration

摘要: The syntheses of the unprotected, (Z)-configurated hexon- and pentonhydroximo-lactones 2a–12a by oxidation D-glucose, cellobiose, D-galactose, D-mannose, 2-acetamido-2-deoxy-D-glucose, D-ribose, D-arabinose oxime with MnO2, Hg(OAc)2, or O2 in presence Cu2Cl2/pyridine are described. An (E/Z)-pair protected hydroximo-lactones 14 15 was obtained diisopropylidene-D-mannose 13 MnO2. In CH2Cl2 solution, minor (E)-isomer slowly transformed into major (Z)-isomer 14. structure assignments for based upon IR NMR data, Beckmann rearrangement 1 14, X-ray analysis 7a 47. From selectively deprotected 2c, 8c, 9c, urethanes 2d, 2f, 8d, 9d were prepared. (E/Z)-mixtures amino phosphates 27/28, 29/30, 31/32 from bromonitroso ethers 16, 19, 17 NaPO(OEt)2. configuration 18 19 assigned on basis their CD spectra correlation corresponding bromonitro 24 25. Factors influencing briefly discussed.