Abnormal Nazarov Reaction. A New Synthetic Approach to 2,3-Disubstituted 2-Cyclopentenones
作者:Shigeo Hirano、Seiji Takagi、Tamejiro Hiyama、Hitosi Nozaki
DOI:10.1246/bcsj.53.169
日期:1980.1
Acid-catalyzed reaction of β,β′-disubstituted cross conjugated dienones or the corresponding ethylene acetals gives mainly 2,3-disubstituted 2-cyclopentenones in stead of the simple Nazarov cyclization products, 3,4-disubstituted 2-cyclopentenones. This transformation is explained in terms of electrocyclic ring-closure, addition of hydroxylic solvent(s), tautomerization of the resulting 2-hydroxycyclopentanone
β,β'-二取代的交叉共轭二烯酮或相应的乙烯缩醛的酸催化反应主要产生 2,3-二取代的 2-环戊烯酮,而不是简单的 Nazarov 环化产物,即 3,4-二取代的 2-环戊烯酮。这种转变是根据电环闭环、羟基溶剂的添加、所得 2-羟基环戊酮中间体的互变异构化,然后是溶剂分解和异构化来解释的。基于该工作假设,公开了一种获得茉莉酮类化合物的新途径,该途径涉及对衍生自取代戊二酸酯的丙烯酰二甲硅烷基醚进行酸处理。