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维蒂希(Wittig)反应是转变羰基化合物为烯烃的一个已知的方法。在此反应中,季鏻盐(3)用碱(通常用苯基锂或醇化金属)通过去质子反应转变为膦内鎓盐(Ylide)或膦烯烯式物(Ylene)(2),它们与羰基化合物作用生成氧化膦(Phosphanoxid)后再转变为烯烃。关于这些在碱性条件下的竞争反应曾有其他作者提到过,此种反应对不活泼的酮类具有重要意义。我们所使用的三氟乙酰基化合物的羰基活性虽然比一般酮类强得多,然而在碱性介质中敌不过与之竞争的卤仿反
Wittig reaction is a known method of converting carbonyl compounds to olefins. In this reaction, the quaternary phosphonium salt (3) is converted to the phosphonium ylide or Ylene (2) by deprotonation using a base (usually with phenyllithium or an alcoholate) (2) With the carbonyl compounds to generate phosphine oxide (Phosphanoxid) and then converted to olefins. In response to these competing reactions under alkaline conditions, other authors have mentioned that such reactions are important for inactive ketones. Although the carbonyl activity of the trifluoroacetyl compounds we use is much higher than that of the common ketones, we can not compete with the haloform in the alkaline medium