SYNTHESIS AND SOME TRANSFORMATIONS OF 1-AZIDO-GLYCOPYRANOSYL CYANIDES- PRECURSORS OF ANOMERIC ALPHA-AMINO-ACIDS

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)-Dxyl o 12 configurations) and C-(1-azido-1-deoxy-D-galactopyranosyl)formami de (19) were prepared from acetylated 1-halogeno-D-glycopryanosyl cyan ides and formamide, resp., by sodium azide in dimethyl sulfoxide. Acet ylated (1S)- 14 and (1R)- 15 1-chloro-D-galactopyranosyl cyanides were obtained from (1R)1-bromo-D-galactopryanosyl cyanide by lithium chlor ide in dimethyl sulfoxide. 1,3-Dipolar cycloaddition of azide ions to the cyano groups of 2 and 16 afforded acetylated 5-(1-azido-1-deoxy-al pha- and -beta-D-galactopyranosyl)tetrazoles 3 and 17, resp., while th at of dimethyl acetylene dicarboxylate to the azido moiety of 2 gave a cetylated dimethyl galactopyranosyl)-1,2,3-triazole-4,5-dicarboxylate 20. Transformation of 3 by ethoxalyl chloride gave acetylated ethyl D- galactopyranosyl)-1,3,4-oxadiazole-5-carboxylate 21. Copyright (C) 199 6 Elsevier Science Ltd