Total Synthesis of (−)-Steganacin via Stereocontrolled Atroposelective Intramolecular Mizoroki-Heck Reaction and Evaluation of Biological Activity

(-)-Steganacin is a lignan with a unique dibenzocyclooctadiene lactone framework. Herein, we describe the total synthesis of (-)-steganacin and its congeners through a stereocontrolled atroposelective intramolecular Mizoroki-Heck reaction. The synthesis of (-)-steganacin was completed in 11 steps from commercial substrates with a 7% overall yield. Furthermore, the biological activities of (-)-steganacin and its synthetic analogues were evaluated. (-)-Steganacin exhibits potent antiproliferation activity against MDA-MB-468 breast cancer cells with IC50 = 0.50 μM.