Fmoc-Dab(Boc)-OH is used in peptide synthesis as a protected derivative of diaminobutyric acid (Dab). The Fmoc (9-fluorenylmethyloxycarbonyl) group serves as a temporary protecting group for the α-amino function, which can be easily removed under basic conditions. Meanwhile, the Boc (tert-butyloxycarbonyl) group protects the side-chain amino group of Dab, enabling precise and efficient control over peptide bond formation. It is commonly employed in solid-phase peptide synthesis (SPPS) to build complex peptides and proteins while preventing unwanted side reactions. The orthogonal nature of these protecting groups allows for selective deprotection: Fmoc with base during chain assembly and Boc with acid in the final cleavage step. Widely applied in biochemical and pharmaceutical research for developing novel peptide-based therapeutics and investigating protein/peptide mechanisms.