Used in the synthesis of antiviral agents, particularly in the development of hepatitis C virus (HCV) inhibitors. It serves as a chiral building block for constructing complex molecules with high stereochemical purity, which is critical for drug efficacy and safety. Its fluorinated pyrrolidinone core enhances metabolic stability and binding affinity in pharmaceuticals. Commonly employed in medicinal chemistry for structure-activity relationship (SAR) studies to optimize drug candidates.