109. A Concise Synthesis of Presilphiperfolane Core through a Tandem TMTU–Co-Catalyzed Pauson–Khand Reaction and a 6π Electrocyclization Reaction-YANG Group

109. A Concise Synthesis of Presilphiperfolane Core through a Tandem TMTU–Co-Catalyzed Pauson–Khand Reaction and a 6π Electrocyclization Reaction

Zichun Zhang, Yuanhe Li, Dandan Zhao, Yingdong He, Dr. Jianxian Gong*, Prof. Dr. Zhen Yang*

Chem. Eur. J. 2017, 23, 1258.

The synthesis of strained polycyclic systems from readily available precursors with a minimum number of steps and with regio- and stereochemical control constitutes an important synthetic challenge. Herein, we report a tandem reaction comprising Co–TMTU (tetramethyl thiourea)-catalyzed Pauson–Khand (PK) and 6π-electrocyclization reactions for the formation of the highly strained core of presilphiperfolanols. The developed chemistry has been applied to the total syntheses of 4-epi-presilphiperfolan-8-ol and 7-epi-presilphiperfolan-1-ol.