Used as a chiral auxiliary and intermediate in asymmetric synthesis, particularly in the preparation of enantiomerically pure pharmaceuticals. Its spirocyclic structure and sulfinyl group enable high stereoselectivity in reactions such as nucleophilic additions and cyclizations. Commonly employed in the development of bioactive molecules, including protease inhibitors and central nervous system agents, due to its ability to control stereochemistry during key bond-forming steps. Also utilized in medicinal chemistry for constructing constrained peptidomimetics and nitrogen-containing heterocycles with improved metabolic stability.