【摘要】 γ-卤一对羟基苯丁酮(1a,1b)、γ-羟基-对苄氧基苯丁酮(2)、β-(对羟苯甲酰基)丙酸(5)、对羟基苯乙酮(8)及其同系物在形成乙二醇缩酮的标准条件下(与乙二醇和催化量对甲苯磺酸在苯中回流脱水)均不形成缩酮;除8外,分别形成相应的γ-乙二醇单醚(3,4)和乙二醇单酯(6)。当对位羟基转化成醚、酯或其他基团和2的羟基被苯甲酰化时,则分别形成稳定性相差颇大的乙二醇缩酮。通过邻近基团参与过程说明了这些不同的行为。更多还原

【Abstract】 p-Hydroxy-γ-halobutyrophenones （1a, 1b）, p-benzyloxy-γ-hydroxy butyrophenone （2）, β-（p-hydroxybenzoyl）propionic acid （5）, and p-hydroxyacetophenone （8, and its lower alkyl homologs） under the standard condition of ethylene ketal formation （HOCH₂CH₂OH-TsOH-C₆H₆ and reflux with removal of water） did not undergo ketal formation and the reaction products were corresponding γ-ethylene glycol monoethers （3, 4） from 1a, 1b and 2 and ethylene glycol monoester （6） from 5, whilst 8 suffered carbonyl-alkyl bond scission. γ-Halobutyrophenones with other para-substituents formed ethylene ketals with varied stabilities. The struotural implications regarding the nonformation of ethylene ketals were discussed.更多还原