Further Observations on the Lead Tetraacetate Oxidation of Reducing Disaccharides

Evidence is presented which supports an earlier suggestion that the linkage-position in a reducing disaccharide may be determined readily by lead tetraacetate oxidation. Compounds examined include aldose and ketose disaccharides and aldobiuronic acids. Two types of reaction—one catalyzed by potassium acetate and the other non-catalyzed—are employed jointly to illustrate oxidation patterns which clearly differentiate each position of the biose linkage. Partial degradation of reducing disaccharides by lead tetraacetate oxidation is illustrated by the preparation of 2-O-α- and 2-O-β-D-glucopyranosyl-D-erythritol and 4-O-β-D-galactopyranosyl-D-erythritol. In turn, 2-O-β-D-glucopyranosyl-D-erythritol is degraded to 2-O-β-D-glucopyranosyl-glycerol.