Total Synthesis of (±)-Brussonol and (±)-Komaroviquinone via a Regioselective Cross-Electrophile Coupling of Aryl Bromides and Epoxides.

The short and stereoselective syntheses of diterpenes (±)-brussonol and (±)-komaroviquinone, via a Ni-catalyzed epoxide ring-opening approach in the presence of aryl halides, is described. Key steps involve the effective preparation of a challenging hemiacetal intermediate in a single operation, followed by a highly efficient BF3·OEt2-catalyzed Friedel-Craft alkylation, to construct the tricyclic skeleton of these diterpenes. The synthetic approach might offer a unified route for the synthesis of several natural products containing icetexane motifs.