烯丙醇在Re 2 O 7的存在下进行转座反应,从而可以通过用一种亲电亲和剂捕获一种异构体来控制平衡。当捕获基团是醛或酮时,可能会发生其他电离,从而导致形成环氧碳鎓离子。通过将双分子亲核加成至中间物来终止该过程,为合成各种含氧杂环化合物提供了一种通用的方法。了解序列中各步骤的相对速率会导致设计反应,从而创建多个具有良好至极佳控制水平的立体中心。
Spiroacetals from dienones and hydroxyenones by mercury(II) cyclisation
作者:William Kitching、Judith A. Lewis、Mary T. Fletcher、James J. De Voss、Richard A. I. Drew、Christopher J. Moore
DOI:10.1039/c39860000855
日期:——
Dienones and hydroxyenones are converted efficiently into spiroacetals by hydroxymercuration–cyclisation followed by either reductive or oxidative removal of mercury.
Transannular Nitrone Cycloaddition. A Stereocontrolled Entry to the Spirocyclic Core of Pinnaic Acid
作者:James D. White、Paul R. Blakemore、Eric A. Korf、Alexandre F. T. Yokochi
DOI:10.1021/ol000361j
日期:2001.2.1
[figure: see text] Thermolysis of lactone 18 initiated a stereospecifictransannular nitrone-olefin [3 + 2] cycloaddition to yield tetracycle 19. Methanolysis followed by reductive cleavage of the isoxazolidine yielded 20, representing the azaspirocyclic core of pinnaic acid (1).