作者:J. Libman、M. Sprecher、Y. Mazur
DOI:10.1016/s0040-4020(01)82743-5
日期:1969.1
dimerization occurs by an acid catalysed aldol-type condensation, while the anhydrides act as dehydrating agents converting the initially formed dimeric ketol to the β,γ-unsaturated ketone 4. Formation of dimeric ketone 4 was also observed when the α-bromoketone 8 was treated with zinc and ethyl chlorocarbonate. In the presence of zinc and zinc chloride however, ketone 8 yielded the dimeric β-diketone 12
甾族酮1与三氯乙酰基对甲苯磺酸酯反应,除烯醇甲苯磺酸酯3外,还得到二聚体酮4及其烯醇酯5和6。当将酮1用三氯乙酸酐和对甲苯磺酸处理时,也获得了二聚酮4。高浓度的反应物和酸的存在有利于二聚产物的形成。建议二聚反应是通过酸催化的醛醇缩合反应而发生的,而酸酐起着脱水剂的作用,将最初形成的二聚酮醇转化为β,γ-不饱和酮。4。当α-溴代酮8用锌和氯代碳酸乙酯处理时,也观察到二聚酮4的形成。然而,在锌和氯化锌的存在下,酮8产生二聚体β-二酮12。