Perylenequinone natural products: total synthesis of hypocrellin A.

An efficient and stereoselective total synthesis of the perylenequinone natural product hypocrellin A (1) is described. The key features include a potentially biomimetic 1,8-diketone aldol cyclization to set the centrochiral C7,C7'-stereochemistry, bis(trifluoroacetoxy)iodobenzene mediated oxygenation, a palladium-catalyzed decarboxylation, and an enantioselective catalytic oxidative 2-naphthol coupling to establish the biaryl axial chirality. The helical stereochemistry is formed from an axial chiral intermediate and is then utilized in a dynamic stereochemical transfer to dictate the stereochemistry of the C7,C7'-seven membered ring formed during the aldol cyclization.