1,6-C-H and 1,5-O-Si insertion reactions of alkylidenecarbene derivatives of monosaccharides

A new protocol has been developed for the generation of alkylidenecarbene derivatives of monosaccharides based on the reaction of trimethylsilylazide and Bu2SnO with alpha-cyanomesylates derived from uloses. When this method is applied to conveniently functionalized carbohydrate derivatives it provides novel heterocyclic ring systems by the rare 1,6-C-H or 1,5-O-Si insertion reactions