Boc-Dap-OH (N^α-Boc-2,3-diaminopropionic acid) is widely used in peptide synthesis as an N-protected amino acid building block. The tert-butoxycarbonyl (Boc) group protects the α-amino group of Dap, enabling selective carboxylic acid activation and coupling while the β-side chain amino group remains available. This facilitates precise incorporation of Dap into peptide sequences. The Boc group is orthogonally deprotected under acidic conditions (e.g., TFA). It is valuable for producing complex peptides, proteins, and peptide-based pharmaceuticals in organic and medicinal chemistry.