Biomimetic Syntheses of (−)-Gochnatiolides A–C and (−)-Ainsliadimer B

We report the first biomimetic syntheses of (−)-gochnatiolides A–C and (−)-ainsliadimer B based on our proposed biogenetic pathway. Our synthesis features one-pot cascade transformations including Saegusa oxidation, intermolecular Diels–Alder cycloaddition, and radical-mediated allylic oxidation, which allow for the rapid generation of (−)-gochnatiolides A–C in a collective manner. We also disclose an unprecedented “copper effect” on the stereochemical outcome of the radical-mediated allylic oxidation. Our synthetic endeavors led to the structural reassignment of (−)-gochnatiolide B. Ultimately, a biomimetic transformation from gochnatiolide B to ainsliadimer B was achieved through a remarkable direct enone hydration.