Utilization of Sugars in Organic Synthesis; Part XXVII. Chemistry of Oxo-Sugars. (2). Regio- and Stereo-Selective Synthesis of Methyl D-Hexopyranosiduloses and Identification of Their Forms Existing in Solutions.

Sixteen oxo derivatives of methyl D-hexopyranosides with various regio- and stereo-chemistries were selectively synthesized by direct oxidation of non-protected methyl glycosides by the bistributyltin oxide-bromine method or by oxidation of pfrtially protected glycosides followed by deprotection. The forms of these oxoglycosides existing in pryidine-d5 and in H2O (D2O) were investigated by means of 13C-NMR spectroscopy, and it was found that interconversion between oxo and hydrate forms of oxoglycosides readily takes place.