Synthesis and determination of the absolute configuration of cavicularin by a symmetrization/asymmetrization approach.

Taking the strain: The asymmetric total synthesis and stereochemical assignment of (-)-cavicularin, which features a highly strained polycyclophane ring system, has been achieved. The key features of this synthesis are 1) macrocyclization by an SN Ar reaction, 2) group-selective reaction to induce planar chirality in a highly stereoselective manner, and 3) radical transannulation to construct the highly strained ring system.