Lin Weimin, Zercher Charles K
Department of Chemistry, University of New Hampshire, Durham, New Hampshire 03824, USA.
J Org Chem. 2007 Jun 8;72(12):4390-5. doi: 10.1021/jo0701379. Epub 2007 May 12.
An efficient formal synthesis of (+)-brefeldin A was accomplished through a synthetic approach that relied upon three keys steps. The five-membered ring was generated in a stereocontrolled fashion through application of a tandem conjugate addition-intramolecular cyclization method developed by Toru. Ring-closing metathesis provided access to a twelve-membered beta-keto lactone, which was ring-expanded to the alpha,beta-unsaturated-gamma-keto lactone through a zinc carbenoid-mediated reaction. Conversion of this lactone to (+)-brefeldin A has been reported previously.
通过一种依赖于三个关键步骤的合成方法，完成了（+）-布雷菲德菌素A的高效形式合成。通过应用Toru开发的串联共轭加成-分子内环化方法，以立体控制的方式生成了五元环。关环复分解反应得到了一个十二元的β-酮内酯，该内酯通过锌卡宾介导的反应扩环为α，β-不饱和-γ-酮内酯。这种内酯转化为（+）-布雷菲德菌素A的方法先前已有报道。
