O-Hydroxy Atorvastatin lactone

O-Hydroxy Atorvastatin lactone is a fluorinated oxidation derivative of Atorvastatin, featuring a pyrrole-fused indole core and a hydroxy-substituted lactone ring. The compound retains the fluorinated tetrahydrofuran moiety of the parent drug but exhibits an additional hydroxyl group at the γ-position of the lactone, formed via oxidative stress-induced cyclization. This structural modification enhances hydrophilicity while reducing lactone ring hydrolysis resistance compared to Atorvastatin. The compound arises as a specific degradation byproduct under alkaline conditions, serving as a critical HPLC reference standard for quantifying oxidative impurities in Atorvastatin formulations.