Boc-Asp(OcHex)-OH, with CAS number 73821-95-1, is a protected derivative of aspartic acid. Its chemical structure features an L-aspartic acid core where the α-amino group is protected by a tert-butoxycarbonyl (Boc) group, and the side-chain β-carboxylic acid is protected as a cyclohexyl (OcHex) ester. This specific protection scheme renders the molecule highly valuable in peptide synthesis. This compound is primarily employed as a key building block in solid-phase and solution-phase peptide synthesis. The Boc protecting group on the amine is stable under basic conditions but can be cleanly removed under acidic conditions, while the cyclohexyl ester on the side chain provides orthogonal protection that is stable to the acidic conditions used for Boc deprotection but can be removed by hydrogenolysis or other methods. This allows for the selective incorporation of aspartic acid into peptide chains, enabling the synthesis of complex peptides and proteins for pharmaceutical research and development. Its application is crucial in the production of therapeutic peptides, where precise control over amino acid sequence and side-chain functionality is essential. The compound is a standard reagent in the toolkit of peptide chemists and is widely available from suppliers specializing in amino acid derivatives and peptide synthesis reagents.