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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