Used as a chiral auxiliary and intermediate in the synthesis of pharmaceuticals, particularly in the production of aspartame, a synthetic sweetener. It plays a key role in asymmetric synthesis due to its ability to control stereochemistry in peptide and peptidomimetic compounds. Also employed in research for developing enzyme inhibitors and receptor ligands, where enantiomeric purity is critical. Its benzyl ester group facilitates protection during peptide coupling reactions, while the p-toluenesulfonate salt enhances solubility and crystallinity for easier handling in organic synthesis.