DEAMINATION OF 2-AMINO-2-DEOXYHEXITOLS AND OF THEIR PER-O-METHYLATED DERIVATIVES WITH NITROUS ACID

Article abstract of DOI:10.1016/0008-6215(80)90008-7

The products of nitrous acid deamination of per-O-methylated 2-amino-2-deoxy-D-glucitol and of 2-amino-2-deoxy-3-O-β-D-galactopyranosyl-D-glucitol and its per-O-methylated derivative have been characterized by g.l.c.-mass spectrometry after treatment with sodium borodeuteride and further substitution by acetylation, methylation, or (trideuteriomethyl)ation.The results confirm that the most important reaction pathway (1) involves a 1<*>2-hydride shift, to give 2-deoxy-D-arabino-hexoses, but that significant side-reactions include (2) solvolytic displacement at C-2, (3) a 3<*>2-hydride shift to give 2-deoxy-2-D-erythro-3-hexuloses, and (4) a C-4<*>C-2 migration to give 2-deoxy-2-C-(hydroxymethyl)-D-ribose and -D-arabinose.Reactions (3) and (4) result in elimination of the original 3-O-substituents, with the exposure of new reducing groups, from oligosaccharides terminated by 3-O-substituted 2-amino-deoxyhexitols.