Danishefsky, Cook, and Polara. JACS, 2006, ASAP. DOI: 10.1021/ja0670254
A very quick synthesis of this compact yet complex natural product, abliet in it’s racemic form. Danishefsky et al. decided to use a rather impressive oxidative dearomatization to construct one ring, allowing a further intramolecular Diels-Alder reaction to complete the core. But they had to make the cyclisation substrate first:
Functionalisation of the aromatic ring was completed easily, with a formylation and bromination of a m-hydroxy-phenol delivering the electrophilic Stille component. Coupling to an allyl silane, and elimination of a mesyl group then finished the cyclisation substrate, which was treated with phenyliodine-(III) diacetate (PIDA):
Good job! Completing the natural product
really took no effort took relatively few transformations; Prilezhaev reaction produced only the desired epoxide, and the exocyclic double-bond was reduced with Wilkinsonâ€™s catalyst. Opening of the epoxide with superhydride and oxidation/deprotection then returned the target. Nice work!