3-Epi empagliflozin Impurity

3-Epi empagliflozin Impurity is a stereoisomer of empagliflozin, characterized by an inversion of configuration at the C-3 position of the glucosidic moiety. It retains the core 1,5-dihydroxy-2-methylpyrrolidin-3-yl scaffold and 4-chlorobenzyl substituent but exhibits altered glycosidic stereochemistry. The molecule contains multiple hydroxyl groups, an ether linkage, and a chloride moiety, contributing to its distinct chromatographic behavior. This impurity arises during synthetic processes due to partial epimerization at the anomeric center. It serves as a critical HPLC reference standard for quantifying stereoisomeric impurities in empagliflozin formulations.