Synthesis of a O-propargyl glycoside suitable for protein modification by Cu(I)-catalyzed cycloaddition

Here we describe the efficient and facile synthesis of N-acetyl glucosamine propargyl O-glycoside, a compound which has been prepared previously by conventional methods. (1) In previous syntheses the glycoside was obtained as a mixture of anomers1a) and in moderate to acceptable yield1b). The described improved method exploits a high yielding and strongly β-selective lanthanide triflate catalysed (2) glycosylation reaction. In addition to reaction efficiency the method is characterised by its simplicity and facile compound isolation and purification.