Boc-3,4-Dehydro-L-proline is a protected derivative of the non-proteinogenic amino acid 3,4-dehydro-L-proline. It features a Boc (tert-butoxycarbonyl) protecting group on the nitrogen atom of the proline ring, which contains a double bond between the 3 and 4 positions. This structural modification introduces rigidity and conformational constraint compared to standard proline. This compound is primarily used as a specialized building block in peptide synthesis and medicinal chemistry research. The dehydroproline moiety is a key structural element for introducing conformational constraints into peptide backbones, which can enhance metabolic stability, modulate biological activity, and improve receptor selectivity. It serves as a crucial intermediate in the synthesis of peptidomimetics and biologically active compounds targeting various therapeutic areas. As a Boc-protected amino acid derivative, it is compatible with standard solid-phase and solution-phase peptide coupling strategies. Its main application lies in the research and development of novel peptide-based drugs and probes, making it a valuable tool in pharmaceutical discovery rather than a commodity chemical.