D-Proline tert-Butyl Ester Hydrochloride is primarily used in organic synthesis and pharmaceutical research. It serves as a chiral building block in the preparation of complex molecules, particularly in the development of peptides and peptidomimetics. Its tert-butyl ester group offers protection for carboxylic acids during multi-step synthetic processes, ensuring selectivity and stability. This compound is also valuable in asymmetric synthesis, aiding in the creation of enantiomerically pure compounds, which are crucial in drug discovery and development. Additionally, it finds application in the study of enzyme inhibitors and receptor ligands, contributing to the exploration of therapeutic agents for various diseases.