Stereodefined Synthesis of Acyclic <i>meso</i> -2,3-Diaryl Dialdehydes and Their Iridium-Catalyzed Enantioselective Desymmetrization

Efficient enantioselective desymmetrization of acyclic meso -dialdehydes has remained unexplored due to limited substrate access. We report a stereodefined synthesis of acyclic meso -2,3-diaryl dialdehydes and their iridium-catalyzed enantioselective desymmetrization to give γ-butyrolactones in up to 96% ee. Hydrogen-donor-free conditions enable in situ Ir–hydride generation for certain substrates. This method enables catalytic asymmetric access to cinncassin A 1 .