Total Synthesis of (±)-Maoecrystal VRezensent(en):Steven V. Ley, James R. Frost
Peking University, Beijing and Shenzen Graduate School of Peking University, P. R. of China
Total Synthesis of (±)-Maoecrystal V
J. Am. Chem. Soc. 2010, 132: 16745-16746
16. Februar 2011 (online)
Wessely oxidative acetoxylation - intramolecular Diels-Alder reaction - rhodium-catalyzed O-H insertion
Maoecrystal V was isolated in 2004 by Sun from the Chinese herb Isodon eriocalyx. Both the congested framework and biological inhibition against HeLa cells (IC50 = 60 nm) has made maoecrystal V a worthy target for the synthetic community.
Key steps involve the formation of the seven-membered ring via a rhodium-catalyzed O-H insertion to give H. The pentacyclic system was completed by use of a Wessely oxidative acetoxylation followed by an intramolecular Diels-Alder reaction in which L was the major product.