Synthesis of a heptasaccharide N-glycan comprising two mannose-6-phosphate residues

A deprotected biantennary high mannose heptasaccharide N-glycan comprising two mannose-6-phosphate residues was synthesised as a putative ligand for the mannose 6-phosphate receptors, using a convergent [3 + 4] glycosylation strategy. [Display omitted] •Convergent [3 + 4] synthesis of an N-glycan heptasaccharide.•Installation of two mannose-6-phosphate residues.•Single step global deprotection by Birch reduction.•Glycosylation of thioglycoside acceptors with trichloroacetimidate donors without aglycon transfer.