Nitrosoamide decomposition. A new method for selective degradation of amino-sugar-containing compounds

Abstract

Methyl glycoside derivatives of 2-acetamido-3,4,6-tri-0-acetyl-2-deoxy-D-glucopyranose and -D-mannopyranose, and a disaccharide derivative containing the former amide, have been N-nitrosated, and the decomposition of the β-glucoside nitrosoamides has been studied. The reaction of the nitrosoamides in aqueous solution to give 3,4,6-tri-O-acetyl-2,5-anhydro-D-mannose, a product of ring contraction, with concomitant release of the aglycone, affords a model for the selective cleavage of such glycosidic linkages in amino-sugar-containing compounds. The α-glycoside nitrosoamides were too labile to be isolated. The methyl β-glycoside nitrosoamide in chloroform solution underwent considerable denitrosation, and gave products of ring contraction and unrearranged pyranoside products.