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。
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 (HOCH_2CH_2OH-TsOH-C_6H_6 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.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1990年第9期913-919,共7页
Acta Chimica Sinica
基金
国家自然科学基金
国家教委资助
