Rules for ring closure: application to intramolecular aldol condensations in polyketonic substrates
作者:Jack E. Baldwin、Michael J. Lusch
DOI:10.1016/0040-4020(82)85023-0
日期:1982.1
An extension of the nomenclature for classifying ring closures to include intramolecular reactions of enolate anions is described, and the rules governing such cyclizations are enumerated. The syntheses of the polyketonic substrates 4-acetyl-2,6-heptanedione (11), 4-acetyl-4-methyl-2,7-octanedione (24), and 3-acetyl-3-methyl-1,6-diphenyl-1,6-heptanedione (33) were carried out, and their base-induced
描述了用于将闭环分类的命名法的扩展,以包括烯醇酸根阴离子的分子内反应,并列举了控制这种环化的规则。聚酮底物4-乙酰基-2,6-庚二酮(11),4-乙酰基-4-甲基-2,7-辛二酮(24)和3-乙酰基-3-甲基-1,6-二苯基的合成-1,6-庚二酮(33),并研究了其碱基诱导的分子内羟醛缩合。对于每种底物,观察到的唯一成环反应是产生6-己烯酮产物的有利的6-(烯lendo)-exo-trig环化反应,该过程在所有情况下都优于竞争性不利的5-(enolendo)-exo-trig闭合,以及其他竞争性青睐的环化。该环化产物的身份12衍生自11,通过芳化证实12至17,并交替地合成17由3-溴-5-甲基苯酚。