Used in solid-phase peptide synthesis as a protected amino acid derivative, enabling the controlled assembly of complex peptides. The Fmoc group provides temporary N-terminal protection that is easily removed under mild basic conditions, while the t-butyl group protects the hydroxyl side chain, ensuring selective reactivity during coupling steps. Its structural rigidity influences peptide conformation, making it valuable in designing foldamers and bioactive peptides with enhanced stability. Commonly applied in the synthesis of collagen-like peptides and other structured proteins where backbone and side-chain stereochemistry are critical.