Used as a chiral building block in the synthesis of pharmaceuticals, particularly in the development of protease inhibitors and antiviral agents. Its rigid, stereospecific structure makes it valuable in asymmetric synthesis, where it helps control the spatial arrangement of atoms in drug molecules. Commonly employed in the preparation of intermediates for HIV and hepatitis C treatments. Also utilized in catalysis and as a ligand in transition metal-catalyzed reactions to produce enantiomerically pure compounds.