Asparagine surrogates for the assembly of N-linked glycopeptide mimetics by chemoselective ligation

Alanine-β-hydroxylamine (Aβx) and alanine-β-hydrazide (Aβz) have been developed as asparagine surrogates for the assembly of N-linked glycopeptide mimetics by chemoselective ligation. The utility of these residues is illustrated with the synthesis of the oligosaccharyl transferase substrate mimetics 1 and 2, and conjugation thereof with GlcNAc to obtain the N-glycopeptide mimetics 3 and 4.