Trimethylsilylnitrate−Trimethylsilyl Azide:  A Novel Reagent System for the Synthesis of 2-Deoxyglycosyl Azides from Glycals. Application in the Synthesis of 2-Deoxy-β-<i>N</i>-glycopeptides

Abstract

A novel reagent system comprising Me(3)SiN(3) and 20 mol % of Me(3)SiONO(2) permits conversion of glycals to 1-azido 2-deoxy sugars in one step in fair to good yields. Galactals offer higher stereoselectivities than do the glucals. Reduction of the azide group with Ph(3)P-H(2)O to amino functionality followed by coupling with amino acids leads to the synthesis of novel 2-deoxy-beta-N-glycopeptides irrespective of the geometry of initial azido sugars. Using this protocol, a new gamma-sugar amino acid derivative is also procured.