Rosuvastatin S- isomer

Rosuvastatin S-isomer is the enantiomer of the parent drug Rosuvastatin, characterized by the opposite absolute configuration at the chiral center (S-configuration) adjacent to the pyrimidine-5-ylmethyl sulfone moiety. It retains the core structure of Rosuvastatin, including the 4-(4-fluorophenyl)-6-isopropyl-5-hydroxy pyrimidine-2,4-dione scaffold but exhibits distinct stereochemical properties. This impurity arises as a byproduct during asymmetric synthesis or resolution processes of the active R-isomer. It serves as a critical HPLC reference standard for enantiomeric purity analysis in Rosuvastatin drug substance characterization.