Prunet Joëlle
Laboratoire de Synthèse Organique, UMR CNRS 7652, Ecole Polytechnique, DCSO, 91128 Palaiseau Cedex, France.
Angew Chem Int Ed Engl. 2003 Jun 30;42(25):2826-30. doi: 10.1002/anie.200301628.
(E)-Alkene units are frequently found in macrocyclic natural products. Among the reactions that form the double bond during the cyclization, the classical Horner-Emmons coupling is still frequently used with success. During the last decade, ring-closing metathesis has emerged as a very powerful tool for the synthesis of large rings, but the E/Z selectivity, which is rarely predictable, depends on many factors which will be discussed in this review. The best solution might be a two-step procedure involving ring-closing alkyne metathesis (RCAM) followed by stereoselective reduction of the macrocyclic alkyne unit to the corresponding E double bond.
（E）-烯烃单元经常出现在大环天然产物中。在环化过程中形成双键的反应中，经典的霍纳尔-埃蒙斯偶联反应仍然经常成功使用。在过去十年中，关环复分解反应已成为合成大环化合物的一种非常强大的工具，但E/Z选择性很少能预测，它取决于许多因素，本文将对此进行讨论。最佳解决方案可能是两步法，包括关环炔烃复分解反应（RCAM），然后将大环炔烃单元立体选择性还原为相应的E型双键。
