Total Synthesis of Cinnamodial-Based Dimer (−)-Capsicodendrin

We describe the first total synthesis of cinnamodial-based dimer (−)-capsicodendrin. First, we developed a 12-step synthetic route to access (−)-cinnamodial from 1-vinyl-2,6,6-trimethylcyclohexene. We then showed that (−)-cinnamodial can selectively dimerize to (−)-capsicodendrin under kinetically controlled basic conditions. Our observations regarding a facile conversion of (−)-capsicodendrin back to (−)-cinnamodial hint at the possibility that (−)-capsicodendrin is a chemical reservoir of insecticidal (−)-cinnamodial and Cinnamosma genus plants release it upon environmental stresses.