Enantioselective Catalytic Desymmetrization of Maleimides by Temporary Removal of an Internal Mirror Plane and Stereoablative Over-reduction: Synthesis of (R)‑Pyrrolam A

A highly enantioselective (>95% ee) strategy to affect the desymmetrization of a maleimide has been performed by temporary attachment to an anthracene template followed by asymmetric reduction with an oxaza­borolidine catalyst. A stereo­ablative over-reduction process was partially responsible for the high levels of enantio­selectivity. Exemplification of the strategy by stereo­selective functionalization and retro-Diels–Alder reaction provided the natural product pyrrolam A.