An Fmoc-protected L-asparagine building block carrying a chitobiose (GlcNAcβ1-4GlcNAc) disaccharide, designed for solid-phase peptide synthesis (SPPS) of glycopeptides. The Nα-Fmoc group is removed under standard base conditions (piperidine) during chain elongation, while the free α-carboxylic acid is available for coupling to the growing resin-bound peptide. The sugar hydroxyl groups are protected as acetate esters (peracetate), which keep the glycan inert during synthesis and are removed under mild base (e.g., sodium methoxide / hydrazine) after assembly. The installed glycan is chitobiose (GlcNAcβ1-4GlcNAcβ-N-Asn), the conserved N-glycan core disaccharide, used to build N-glycopeptides and study N-glycosylation.