作者:Robert Betík、Martin Kotora
DOI:10.1002/ejoc.201100317
日期:2011.6
accomplished. The crucial synthetic step comprised the enantioselective conjugate addition of vinylmagnesium bromide to a chiral imine formed from a trisubstituted cyclic α,β-unsaturated aldehyde with >98 % ee, giving rise to the stereoselectively substituted building block possessing the A–B steroid rings. Further steps included the construction of the side chain containing the triple bond, and the obtained
基于形成具有 A-B 类固醇环骨架的手性双环中间体,通过 12 步从市售四氢萘酮对非天然 (-)-甲氧基雌酮进行对映选择性合成。关键的合成步骤包括将溴化乙烯基镁与手性亚胺进行对映选择性共轭加成,该手性亚胺由具有 >98% ee 的三取代环状 α,β-不饱和醛形成,从而产生具有 A-B 类固醇环的立体选择性取代结构单元。进一步的步骤包括构建包含三键的侧链,并将获得的烯炔进行 Pauson-Khand 反应,立体选择性地提供中间体四环酮。进一步的官能团转化产生了目标化合物。