Used in solid-phase peptide synthesis as a chiral building block for introducing a terminal alkene handle into peptide chains. The Fmoc group allows for mild base-labile protection during stepwise synthesis, while the pentenyl side chain provides a site for post-assembly modifications, such as thiol-ene coupling or ring-closing metathesis. Enables the construction of cyclic peptides, peptide dendrimers, or bioconjugates with controlled architecture. Particularly valuable in drug discovery and chemical biology for creating functionally diverse peptide libraries.