Convergent Total Synthesis of (−)-Calidoustene

Abstract

The first total synthesis of the sesterterpenoid (−)-calidoustene has been accomplished, featuring a stereoselective Michael/aldol cascade to construct the trans-hydrindane backbone, a tandem Pummerer/Sakurai cyclization to establish the bicyclo[3.2.1]octane framework, a metallaphotoredox enone coupling followed by MHAT-initiated cyclization to forge the congested central C-ring, and late-stage functionalization via Cu-catalyzed desaturation and diimide reduction.