Synthesis and some transformations of 1-azido-glycopyranosyl cyanides - Precursors of anomeric α-amino acids

Article abstract of DOI:10.1016/0040-4020(96)00440-1

Acetylated 1-azido-glycopyranosyl cyanides (of the (1R)- 2, and (1S)-D-galacto 16, (1S)-D-arabino 5, (1R)-D-gluco 7 (1R)-11, and (1S)-D-xylo 12 configurations) and C-(1-azido-1-deoxy-D-galactopyranosyl)formamide (19) were prepared from acetylated 1-halogeno-D-glycopyranosyl cyanides and formamide, resp., by sodium azide in dimethyl sulfoxide. Acetylated (1S)- 14 and (1R)- 15 1-chloro-D-galactopyranosyl cyanides were obtained from (1R)1-bromo-D-galactopyranosyl cyanide by lithium chloride in dimethyl sulfoxide. 1,3-Dipolar cycloaddition of axide ions to the cyano groups of 2 and 16 afforded acetylated 5-(1-azido-1-deoxy-α- and -β-D-galactopyranosyl)tetrazoles 3 and 17, resp., while that of dimethyl acetylene dicarboxylate to the azido moiety of 2 gave acetylated dimethyl 1-(1-azido-1-deoxy-β-D-galactopyranosyl)-1,2,3-triazole-4,5-dicarboxy late 20. Transformation of 3 by ethoxalyl chloride gave acetylated ethyl 2-(1-azido-1-deoxy-α-D-galactopyranosyl)-1,3,4-oxadiazole-5-carboxyla te 21.