Used in peptide synthesis as a chiral building block, particularly in the preparation of modified amino acids with alkyne functionality for click chemistry applications. The alkyne group allows for selective conjugation via copper-catalyzed azide-alkyne cycloaddition (CuAAC), enabling efficient labeling or bioconjugation. The Fmoc group provides orthogonal protection for amine functionality, compatible with solid-phase peptide synthesis (SPPS), making it valuable in the development of peptide-based drugs, probes, and biomaterials. Its (R)-configuration ensures stereochemical control in the synthesis of enantiomerically pure peptides.