Used as a key intermediate in the synthesis of antiviral and antitumor agents, particularly in the development of nucleoside analogs. Its rigid bicyclic structure with a defined stereochemistry enhances selectivity in drug design, especially for targeting viral polymerases. The ethynyl group allows for further functionalization via click chemistry, enabling rapid derivatization in medicinal chemistry campaigns. Commonly employed in the preparation of protease inhibitors and other bioactive molecules where conformational restraint improves metabolic stability and binding affinity.