Velpatasvir intermediate I- RR isomer

Velpatasvir intermediate I- RR isomer is a stereoisomeric analog of the antiviral drug velpatasvir, featuring a (1R,2R)-configured tetrahydrofuran core fused to a 4-aminopyrrolidin-2-one scaffold. The compound contains a sulfonamide moiety at the C-5 position of the pyrrolidin-2-one ring, linked to a substituted benzene ring via a methylene bridge. This isomer diverges from the parent drug by the absolute stereochemistry at the tetrahydrofuran chiral centers, leading to distinct enantiomeric purity challenges during API synthesis. It serves as a stereoisomeric reference standard for HPLC-based impurity profiling in velpatasvir active pharmaceutical ingredient batches.