Fragmentation of Carbohydrate Anomeric Alkoxyl Radicals. A New Synthesis of Chiral β-Iodo Azides, Vinyl Azides, and 2<i>H</i>-Azirines

The reaction of 3-azido-2,3-dideoxy-hexopyranose compounds from the d-gluco, d-galacto, d-lacto, and l-arabino carbohydrate series, with (diacetoxyiodo)benzene and iodine, generated 2-azido-1,2-dideoxy-1-iodo-alditols with one carbon less than the starting carbohydrate. These β-iodo azides could be transformed by dehydroiodination into vinyl azides, which in turn afforded 3-monosubstituted 2H-azirines under thermal conditions. These β-iodo azides and 2H-azirines may be interesting chiral synthons for the preparation of more complex heterocyclic systems.