Protecting‐Group‐Dependent Stability of Intersaccharide Bonds—Synthesis of a Fucosyl‐Chitobiose Glycopeptide

Acetyl-protecting groups in the Fucose moiety stabilize the intersaccharide bonds of 1 such that they are not ruptured during the cleavage of the C-terminal tert-butyl protecting groups with trifluoroacetic acid. Benzyl-protecting groups do not bring about such a stabilization. This effect, which is important for planning and carrying out the synthesis of complex glycopeptides, enables the construction from 1 of a trisaccharide hexapeptide which corresponds to a partial structure of the linking region of the envelop protein of a leukemia virus.