Stereoselective Synthesis of α‐Glycosyl Azides by TMSOTf‐Mediated Ring Opening of 1,6‐Anhydro Sugars

Access to α‐glycosyl azides in modest to high diastereoselectivity by way of TMSN 3 ring‐opening of 1,6‐anhydro sugars mediated by TMSOTf is reported. The reaction tolerates a wide variety of functional groups including alcohol, alkyne, azide and ester groups. The efficient synthesis of a pseudopentasaccharide in five steps from commercially available levoglucosan by way of a “click‐click” approach is presented to highlight the interest of the TMSN 3 ring‐opening reaction.