O-Glycosyl Trichloroacetimidates Bearing Fmoc as Temporary Hydroxy Protecting Group: A New Access to Solid-Phase Oligosaccharide Synthesis

Different O-glycosyl trichloroacetimidates bearing base sensitive Fmoc protected hydroxy groups were efficiently prepared with CCl(3)CN using a catalytic amount of sodium hydride. The resulting glycosyl donors were engaged in glycosylation reactions both in solution and on solid support with a new ester-type linker with good results. In both approaches, Fmoc groups were afterward quantitatively cleaved using mild basic conditions.