Total Synthesis and Determination of the Absolute Configuration of Berkeleylactone I

Herein, we report the first total synthesis of berkeleylactone I and its 12S diastereomer. Consequently, this chemical synthesis allowed us to establish the unknown absolute stereochemistry at the C-12 center as 12R, which was unidentified by the isolation group. This synthetic approach includes several critical reactions, such as the Sharpless asymmetric dihydroxylation, Baran's Ni-catalyzed alkyl-alkyl cross-coupling reaction, Brown allylation, Mitsunobu reaction, and ring-closing metathesis, as key steps.