of (E)-5-bromo-3-penten-2-one with triphenylphosphine affords a 3:1 mixture of two protomeric phosphonium salts 4-oxo 2 pentenyltriphenylphosphonium bromide and 4-oxo-1-pentenyltriphenyl-phosphonium bromide, characterized by the 13C NMR spectrum of the mixture. However, the common phosphorane of these salts gives two condensation products with benzaldehyde, corresponding to α- and γ-condensation respectively
(E)-5-
溴-
3-戊烯-2-酮与
三苯基膦的反应,得到两种原始meric盐的3:1混合物:4-氧代2
戊烯基三苯基
溴化and和4-氧代-1-
戊烯基三苯基-混合物的13 C NMR谱。但是,这些盐的常见
磷烷会生成两个与
苯甲醛的缩合产物,分别对应于α和γ缩合。