lieben反应是指在卤素和氢氧化钠(次氯酸钠)作用下,把甲基酮转化为羧酸盐和卤仿的反应,也称卤仿反应。如果所用的卤素为碘,则称为碘仿反应,常用作鉴别甲基酮的显色反应。
反应机理
由上述反应机理可以看出,反应中氢氧化钠除了作为碱外,还作为亲核试剂。如果使用其它碱,使反应在无水条件下进行,则反应生成的卤仿碳负离子可作为亲核试剂与其它亲电试剂反应,这是langlois建立的三氟甲基化方法。
反应实例
参考文献
1. serullas. effect of iodine on thebasic solution of alcohols. ann. chim. (paris) [13] 1822, 20, 165.
2. von liebig, j. reaction ofalcohols with chlorine gas. ann. phys. chem. ser. 2 1831, 23, 444.
3. lieben, a. the formation ofiodoform and the application of this reaction in the chemical analysis. liebigs ann.chem. 1870, supp. 7, 218-236.
4. hailes, h. c., isaac, b., hashimjavaid, m. synthesis of methyl epijasmonate and cis-3-(2-oxopropyl)-2-(pent-2z-enyl)-cyclopentan-1-one.tetrahedron 2001,57, 10329-10333.
5. storm, j. p., andersson, c.-m.iron-mediated synthetic routes to unsymmetrically substituted, stericallycongested benzophenones. j. org. chem. 2000, 65, 5264-5274.
6. bennasar, m. l., vidal, b.,bosch, j. total synthesis of indole alkaloids of the ervatamine group. abiomimetic approach. j. org. chem.
1996,61, 1916-1917.
7.ihara, m., taniguchi, t., tokunaga, y., fukumoto, k. ring contraction ofcyclobutanes and a novel cascade reaction: application to synthesis of (±)-anthoplalone and (±)-lepidozene. j. org. chem. 1994, 59, 8092-8100.
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