Used as a chiral building block in the synthesis of pharmaceuticals, particularly in the development of enzyme inhibitors and bioactive molecules. Its free amine (as hydrochloride salt) and differentially protected ester functionalities (tert-butyl and methyl esters) allow for selective deprotection and reactions in multi-step organic syntheses. Commonly employed in the preparation of peptidomimetics and other nitrogen-containing heterocycles where stereochemistry is critical for biological activity. The hydrochloride salt form enhances stability and handling during industrial-scale reactions.