Asymmetric Total Synthesis of Lancifodilactone G Acetate. 1. Diastereoselective Synthesis of CDEFGH Ring System

作者:Sun, Tian-Wen; Liu, Dong-Dong; Wang, Kuang-Yu; Tong, Bing-Qi; Xie, Jia-Xin; Jiang, Yan-Long; Li, Yong; Zhang, Bo; Liu, Yi-Fan; Wang, Yuan-Xian; Zhang, Jia-Jun; Chen, Jia-Hua*; Yang, Zhen*
来源:Journal of Organic Chemistry, 2018, 83(13): 6893-6906.
DOI:10.1021/acs.joc.7b02915

摘要

The stereoselective construction of the CDEFGH ring system of lancifodilactone G is described. The key steps in this synthesis are (i) ring-closing metathesis for formation of the oxa-bridged eight-membered ring; (ii) an intramolecular Pauson-Khand reaction for construction of the sterically congested F ring; and (iii) sequential cross-metathesis, hydrogenation, and lactonization reactions for installation of the anomerically stabilized bis-spiro ketal fragment of lancifodilactone G.