This compound is a chiral, protected amino acid derivative, specifically (S)-2-((tert-butoxycarbonyl)amino)-5-((2,2,10,10-tetramethyl-4,8-dioxo-3,9-dioxa-5,7-diazaundecan-6-ylidene)amino)pentanoic acid, used as a building block in advanced peptide synthesis. The tert-butoxycarbonyl (Boc) group protects the α-amino function, preventing unwanted reactions during peptide bond formation and allowing selective deprotection under acidic conditions. The complex side-chain substituent at the 5-position, featuring a diazaundecane ylidene moiety, acts as an orthogonal protecting or linking group, enabling precise control in multi-step syntheses, such as solid-phase peptide assembly or conjugation reactions. This structure provides enhanced stability, solubility in organic solvents, and compatibility with complex molecular constructions. It is essential in pharmaceutical research for developing peptide-based drugs, bioactive molecules, and bioconjugates requiring high specificity and structural integrity.