Glycosylidene Carbenes a new approach to glycoside synthesis. Part 1. Preparation of glycosylidene‐derived diaziridines and diazirines

A new approach towards the synthesis of glycosides based upon a (formal) insertion of glycosylidene carbenes into OH bonds is presented. The synthesis and characterization of the glycosylidene‐derived diazirines 25 – 28 , precursors of glycosylidene carbenes, are described. The diazirines were prepared by the rapid, high‐yielding oxidation of the diaziridines 20 and 22 – 24 with I 2 /Et 3 N. The diaziridines, the first examples of C ‐ alkoxy‐diaziridines, were formed in high yields by the reaction of the [(glycosylidene)‐amino]methanesulfonates 14 and 17 – 19 with a saturated solution of NH 3 in MeOH. The diazirines are highly reactive compounds, losing N 2 at room temperature or below. The reaction of the gluco ‐configurated diazirine 25 with i‐PrOH yielding a mixture of the α‐ and β‐ D ‐glucosides 29 and 30 illustrates the potential of glycosylidene‐derived diazirines as a new type of glycosyl donors.