An Effective and Highly Stereoselective Julia Olefination of Cyclopropyl Carbinol Mediated by CeCl<sub>3</sub>·7H<sub>2</sub>O/NaI
作者:Wei-Dong Z. Li、Yu Peng
DOI:10.1021/ol051051+
日期:2005.7.1
text] An efficient and highly stereoselective synthesis of functionalized trisubstituted E-olefins from cyclopropyl carbinol derivatives via a Julia-type olefination mediated by an intriguing Lewis acidic system consisting of CeCl(3).7H(2)O and NaI in refluxing acetonitrile is reported. This facile olefination allows for the iterative incorporation of methylcyclopropyl ketone as a C(5) prenylation synthon
[反应:见正文]通过有趣的Lewis酸性系统介导的由CeCl(3).7H(2)O和NaI组成的奇特的Lewis酸性系统,通过Julia型烯化反应,从环丙基甲醇衍生物中高效,高度立体选择性地合成官能化的三取代E-烯烃。据报道乙腈回流。这种简便的烯烃化反应允许在无环萜烯类化合物的合成中以迭代的方式将甲基环丙基酮作为C(5)戊烯基化合子并入,如青草醇6E-异构体12,生物学上重要的二萜二醇和天然存在的二萜17的简便合成所证明的那样。