A unified strategy for the synthesis of (−)-maoecrystal Z, (−)-trichorabdal A, and (−)-longikaurin E

Herein we describe in full our investigations that led to the completion of the first total syntheses of (−)-maoecrystal Z, (−)-trichorabdal A, and (−)-longikaurin E. The unified strategy employs a TiIII-mediated reductive epoxide coupling to rapidly prepare a key spirolactone. Highly diastereoselective SmII-mediated reductive cyclizations and a PdII-mediated oxidative cyclization enable the construction of three architecturally distinct ent-kauranoid frameworks from this common intermediate.

Figure optionsDownload as PowerPoint slide