Used in solid-phase peptide synthesis to incorporate a protected lysine derivative with orthogonal protection. The Fmoc group allows for mild base deprotection while the Boc group remains stable, enabling selective deprotection in multi-step peptide assembly. The hydroxyl group on the side chain provides a handle for further modifications, such as glycosylation or conjugation to linkers and tags. Commonly applied in the synthesis of complex peptides, glycopeptides, and peptide-based pharmaceuticals where precise side-chain functionalization is required. Also valuable in the preparation of peptide arrays and bioconjugates for research and diagnostic applications.