Convenient Synthesis of 2‐Azido‐2‐deoxy‐aldoses by Diazo Transfer

Diazo transfer from trifluoromethanesulfonyl azide (TfN3) to 2‐amino‐2‐deoxy‐glycoses constitutes a high‐yielding, simple procedure for the preparation of partially protected or unprotected 2‐azido‐2‐deoxy‐aldoses. Thus, the D‐allosamine derivative 2 gave 93% of 3, while diazo transfer to D‐glucosamine, D‐mannosamine, and D‐galactosamine, followed by acetylation, yielded the azides 5, 7, and 9 in yields of 74–91, 65, and 70%, respectively.