Total Synthesis of (–)-Sessilifoliamide C and (–)-8-epi-Stemoamide
摘要:
A convergent route featuring [3,3]-sigmatropic rearrangements of a linchpin azepinopyrrolidine served to install two of the four contiguous stereocenters present in the tricyclic Stemona alkaloids sessilifollamide and stemoamide. In addition to the first total synthesis of (-)-sessilifoliamide C, a potential biosynthetic relationship between the sessilifoliamides and previously reported Stemona alkaloids is presented.
Total Synthesis of (–)-Sessilifoliamide C and (–)-8-<i>epi</i>-Stemoamide
作者:Adam T. Hoye、Peter Wipf
DOI:10.1021/ol200743u
日期:2011.5.20
A convergent route featuring [3,3]-sigmatropic rearrangements of a linchpin azepinopyrrolidine served to install two of the four contiguous stereocenters present in the tricyclic Stemona alkaloids sessilifollamide and stemoamide. In addition to the first total synthesis of (-)-sessilifoliamide C, a potential biosynthetic relationship between the sessilifoliamides and previously reported Stemona alkaloids is presented.
An efficient diastereoselective synthesis of (−)-stemoamide has been accomplished from a pyroglutamic acid derivative in eight steps and with 24% overall yield. The synthesis features an intramolecular samarium diiodide-promoted 7-exo-trigcyclization of a ketyl radical generated from the corresponding aldehyde.