Used in peptide synthesis as a chiral building block for introducing a β-amino acid residue with a phenyl-containing side chain. The Fmoc group allows for solid-phase synthesis by providing orthogonal protection, enabling sequential coupling and deprotection under mild basic conditions. Its (S)-configuration ensures stereochemical control in the construction of foldamers and bioactive peptides. The 5-phenylpentanoic acid moiety can enhance peptide stability and influence secondary structure due to hydrophobic interactions. Commonly applied in medicinal chemistry for developing enzyme inhibitors or peptidomimetics where aromatic and aliphatic spacing is required.