Conversion of glycals into vicinal-1,2-diazides and 1,2-(or 2,1)-azidoacetates using hypervalent iodine reagents and Me 3 SiN 3 . Application in the synthesis of N-glycopeptides, pseudo-trisaccharides and an iminosugar

Glycals react with PIFA (or PIDA)–TMSN 3 in presence of TMSOTf to form sugar derived 1,2-diazides and vicinal azidoacetates. Synthesis of 2-azido- N -glycopeptides, pseudotrisaccharides, and a piperidine triol derivative is reported.