Used as an intermediate in the synthesis of antiviral drugs, particularly in the production of nucleoside analogs like lamivudine and emtricitabine, which are key components in HIV and hepatitis B treatments. Its five-membered ring structure with oxygen and sulfur atoms provides a stable scaffold for modifying sugar moieties in nucleoside chemistry. Also employed in the development of chiral auxiliaries and asymmetric synthesis due to its stereochemical properties.