Degradation of carbohydrates. VI. Isolation and structure of some Glycos-2-enes

Abstract

The action of lime-water on 2,3-di-O-methyl-D-glucose has yielded crystalline 3-deoxy-2-O-methyl-ß-D-erythro-hexofuranos-2-ene, which showed a complex muta-rotation involving the a-furanosene and the a-pyranosene forms. Acetylation gave 1,4,6-tri-O-acetyl-3-deoxy-2-O-methyl-a-D-erythro-hexopyranos-2-ene. Crystalline products shown to have the a-pyranosene form were obtained from 2,3,4-tri-O-methyl-D-glucose, 2,3,4,6-tetra-O-methyl-D-glucose, and 2,3,4-tri-O-methyl-D-galactose. The ring forms, anomeric configurations, and conformations of the products were determined, largely, by nuclear magnetic resonance spectroscopy.