(1R,3S)-3-((((9H-Fluoren-9-yl)methoxy)carbonyl)amino)cyclopentanecarboxylic acid is primarily used in peptide synthesis as a protected amino acid derivative. The fluorenylmethoxycarbonyl (Fmoc) group serves as a protecting group for the amine functionality, allowing selective deprotection during solid-phase peptide synthesis. This compound is particularly valuable in the synthesis of complex peptides and proteins, where precise control over the sequence and protection of amino acids is critical. Its cyclopentane backbone can also contribute to the conformational stability of the synthesized peptides, making it useful in the development of peptide-based drugs and biomaterials. Additionally, it finds applications in research settings for studying peptide structure-activity relationships and designing novel therapeutic agents.