Synthesis of 7-Deoxyxestobergsterol A, a Novel Pentacyclic Steroid of the Xestobergsterol Class

摘要

In summary, we have achieved the first total synthesis of a pentacyclic steroid of the xestobergsterol class by an efficient route, which utilizes the Breslow remote functionalization process. In this way, 7-deoxyxestobergsterol A (1d) is available in 17 steps and 10/100 overall yield from the known alcohol 9 (22 steps and 7/100 overall yield from stigmasterol (8)).