Widely used in peptide synthesis, this compound serves as a protected amino acid building block, enabling stepwise assembly of peptides with high precision. The Fmoc group allows for mild base-induced deprotection, while the allyl ester offers orthogonal protection for the carboxylic acid, which can be selectively removed under neutral conditions using palladium catalysts. This makes it valuable in solid-phase peptide synthesis, especially when synthesizing complex peptides requiring selective side-chain deprotection. Its hydrochloride salt form enhances stability and solubility in common polar solvents, facilitating handling and coupling efficiency.