Used in peptide synthesis as a chiral building block for the preparation of modified peptides with enhanced stability and biological activity. The Fmoc group enables solid-phase synthesis by providing orthogonal protection for the amine function, allowing stepwise assembly of complex peptide sequences. The valerolactam core introduces conformational constraints, which can improve receptor selectivity and metabolic resistance in peptide-based drug candidates. Commonly applied in the development of protease inhibitors and bioactive peptidomimetics in medicinal chemistry research.