Isopropyl Tri-O-acetyl-α-D-hexopyranosulosides. The Configurations of the Parent Oximes

Abstract

A variety of methods are described for the deoximation of isopropyl tri-O-acetyl-2-oximino-α-D-arabino-hexopyranoside (1) to isopropyl tri-O-acetyl-α-D-arabino-hexopyranosuloside (3). Using acetaldehyde in acetonitrile and hydrochloric acid, both 3 and its lyxo-isomer (4), from the corresponding oxime (2), were obtained in crystalline form. Comparisons of the chemical shifts of the anomeric hydrogens of the ulosides with those of the corresponding oximes require the oximes to possess the C-1/OH syn- or Z-configuration.