A Short, Catalytic, Asymmetric Synthesis of Diospongins A and B by a One‐Pot, Sequential Hetero‐Diels–Alder/Mukaiyama–Michael Reaction Process

Abstract

Abstract A new route to the diarylheptanoid diospongins A and B was developed. The key step is a novel, one‐pot, sequential dirhodium(II) tetrakis[( S )‐3‐(benzo‐fused phthalimido)‐2‐piperidinonate] [Rh 2 ( S ‐BPTPI) 4 ] catalyzed enantioselective hetero‐Diels–Alder/TMSOTf‐catalyzed Mukaiyama–Michael reaction process. The sign of the optical rotation of natural diospongin B was determined to be (+) and not (–) as was originally reported.