The synthesis of α-, β- and γ-substituted α-phosphono-γ-lactones was accomplished using different ring closure and ring homologation strategies. It was found that the lactones could be selectively transformed into the corresponding ethyl cyclopropanecarboxylates by treatment with sodium ethoxide in boiling THF. The reported reaction provides an attractive alternative to the classical homologous HornerâWadsworthâEmmons approach to the construction of cyclopropanes with electron-withdrawing functionalities.
通过不同的环闭合和环同系化策略,成功合成了α-、β-和γ-取代的α-
磷酸-γ-内酯。研究发现,这些内酯可以通过在沸腾的
四氢呋喃中用
乙醇钠处理,选择性地转化为相应的
乙基环丙烷羧酸酯。所报道的反应为构建带有吸电子功能的
环丙烷提供了一种吸引人的替代方法,超越了经典的同系化Horner-Wadsworth-Emmons方法。