The azidonitration of tri-O-acetyl-D-galactal

Abstract
Reaction of 3,4,6-tri-O-acetyl-D-galactal with excess ceric ammonium nitrate and sodium azide in acetonitrile produced 2-azido-1-nitrate addition products (53% .beta.-galacto, 22% .alpha.-galacto and 8% .alpha.-talo) and N-acetyl-3,4,6-tri-O-acetyl-2-acido-2-deoxy-.alpha.-D-galactopyranosylamine was formed, on hydrolysis, in 10% yield. The reaction product provides a convenient source of D-galactosamine and 3,4,6-tri-O-acetyl-2-acido-2-deoxy-.alpha.-D-galactopyranosyl halides. The crystalline .beta.-chloride is reported. The use of these glycosyl halides as reactants for the preparation of 2-acido-2-deoxy-.alpha. and -.beta.-D-galactopyranosides under conditions promoted by both mercuric cyanide and silver salts are reported.