Synthesis of N-glycyl-β-glycopyranosylamines, derivatives of main human secreted oligosaccharide core structures

β-Glycopyranosylamines were synthesized by the reaction of ammonium carbamate with di-, tetra-, and hexasaccharides, corresponding to the human milk and urine oligosaccharide core structures, in aqueous methanolic solution in the presence of NH3. The N-acylation of these β-glycopyranosylamines with N-Boc-glycine N-hydroxysuccinimide ester followed by removal of the Boc group afforded N-glycyl-β-glycopyranosylamines of the corresponding oligosaccharides in yields of up to 60%.