Glycosyl azides of sugar 2-sulfonic acids

Phenyl and trityl 2-O-sulfonyl-1-thio-α-d-manno- and β-d-glucopyranosides were reacted with sodium azide to yield 2-S-phenyl or 2-S-trityl-d-gluco- and d-mannopyranosyl azides, respectively. Usually, both anomers were formed in approximately equal amounts and formation of glycals was also observed in some cases. The product distribution of these reactions depends on the nature of the aglycone, the applied reagent and also on the solvent. These results can be rationalised by the intermediacy of episulfonium as well as oxocarbenium ions. Oxidation of the 2-S-trityl-α-d-glucopyranosyl or α-d-mannopyranosyl azides by Oxone®, gave sodium 2-sulfonato-α-d-gluco- and α-d-mannopyranosyl azides, respectively.