Iterative Cyclopropanation: A Concise Strategy for the Total Synthesis of the Hexacyclopropane Cholesteryl Ester Transfer Protein Inhibitor U-106305
作者:Anthony G. M. Barrett、Dieter Hamprecht、Andrew J. P. White、David J. Williams
DOI:10.1021/ja9708326
日期:1997.9.1
The first enantioselective total synthesis of the hexacyclopropane natural product U-106305, which is produced by Streptomyces sp. UC 11136, is described in full detail. Considerations on the biosynthesis of U-106305 and its close resemblance to the pentacyclopropane bacterial metabolite FR-900848 (10) led to the proposal that its previously unknown stereostructure should be represented as 11. The
第一个对映选择性全合成六环丙烷天然产物 U-106305,由 Streptomyces sp. 产生。UC 11136 进行了详细描述。考虑到 U-106305 的生物合成及其与五环丙烷细菌代谢物 FR-900848 (10) 的相似性,建议其先前未知的立体结构应表示为 11。11 的中央 C2 对称五环丙烷单元由以有效的双向方法重复使用三步环丙烷“同源”序列。去对称的五环丙烷 23 被转化为二烯醇 13,二烯醇 13 被立体和区域选择性地单环丙烷化以提供六环丙烷 25。通过转化为硫醚 29 和脱硫来实现脱氧。