Synthesis of glycoprotein N-chain core fragment GlcNAcβ1-4(Fucα1-6)GlcNAc

Synthesis of Ac₃GlcNAcβ(1-4)-3-Ac-6-BnGlcNTrocβ-O(CH₂)₃NHCOCF₃, a convenient precursor for the preparation of 6-substituted derivatives of disaccharide GlcNAcβ1-4GlcNAc, is described. α-Fucosylation of this precursor after the removal of protection groups leads to the title trisaccharide, whereas O-sulfation results in 6-O-sulfated derivative of chitobiose.