Total Syntheses of Crinipellins Enabled by Cobalt-Mediated and Palladium-Catalyzed Intramolecular Pauson-Khand Reactions.

Efficient total syntheses of the naturally occurring, potent antibiotic compounds (-)-crinipellin A and (-)-crinipellin B are described. The key advanced intermediate, a fully functionalized tetraquinane core, was constructed by a novel thiourea/palladium-catalyzed Pauson-Khand reaction. This intermediate can serve as a common intermediate for the collective total synthesis of other members of the crinipellin family.