Used as a chiral building block in the synthesis of peptide-based pharmaceuticals, particularly in the development of protease inhibitors. Its protected amine and disulfide-containing side chain make it valuable for constructing complex peptides with defined stereochemistry. Commonly employed in solid-phase peptide synthesis where the Boc group allows for controlled deprotection and chain elongation. The methyldisulfanyl group can be selectively reduced to a thiol for further functionalization or disulfide bond formation, which is critical in mimicking the structure and function of natural bioactive peptides.