Concise Total Syntheses of Palominol, Dolabellatrienone, β-Araneosene, and Isoedunol via an Enantioselective Diels−Alder Macrobicyclization

Concise total syntheses of four members of the dolabellane family of diterpenoid natural products are reported. Key features of the developed route include the first demonstration of an enantioselective, intramolecular Type I Diels−Alder macrobicyclization, the first example of a stereoselective π-allyl Stille coupling reaction involving a farnesyl-derived intermediate, a powerful new reagent for the formation of dithianes with acid-sensitive molecules, and a unique and highly efficient ring-contraction sequence based on a modified Wolff photochemical rearrangement.