Nitrous acid deamination of methylated amino-oligosaccharide glycosides

Abstract

G.l.c.-mass spectrometry has been used to characterize the products of N-deacetylation-nitrous acid deamination of per- O-methylated derivatives ( 8–11) of methyl 2-acetamido-2-deoxy-3- O-β- D-galactopyranosyl-α- D-glucopyranoside( 1), methyl ( 2) and benzyl ( 3) 2-acetamido-2-deoxy-4- O-β- D-galactopyranosyl-β- D-glucopyranosides, and methyl 2-acetamido-2-deoxy-6- O-β- D-galactopyranosyl-α- D-glucopyranoside ( 4). 2,5-Anhydrohexoses have been converted into alditol trideuteriomethyl ethers, alditol acetates, and aldononitriles. The importance of side reactions that lead to the formation of 2-deoxy-2- C-formylpentofuranosides is discussed.