Used as an intermediate in the synthesis of antiviral medications, particularly in the development of nucleoside analogs that target RNA viruses. Its structure enables incorporation into viral RNA chains, leading to chain termination and inhibition of viral replication. Commonly applied in the production of drugs aimed at hepatitis C and other viral infections, where stereochemistry plays a critical role in efficacy and metabolic stability. The phosphorothioate and sugar modifications enhance resistance to enzymatic degradation, improving bioavailability and prolonging antiviral activity.