The reaction of cyclohexanone enamines with α,β-unsaturated acid chlorides and 2- and 3-chloropropanoyl chlorides under various conditions has been investigated. a,ae-Annulation of enamines Ia-Ie occurs on treatment with chlorides IIa-IId or 3-chloropropanoyl chloride to give bicyclo[3.3.1]nonane-2,9-dione derivatives III. The formation of isomeric bicyclononanediones IIIe and IIIh and chromanones VIIIa and VIIIb in the reaction of enamines derived from substituted cyclohexanones suggests that the cyclization might proceed also by another pathway than via [3,3] sigmatropic rearrangement. Based on the reaction course and product distribution in these reactions, a parallel reaction pathway involving a C-acylation-Michael addition has been suggested.
环己酮亚胺与α,β-不饱和酰
氯以及2-和
3-氯丙酰氯在不同条件下的反应已经进行了研究。
亚胺Ia-
Ie与
氯IIa-
IId或
3-氯丙酰氯反应,发生α,α-环化,得到双环[3.3.1]
壬烷-2,9-二酮衍
生物III。当
环己酮衍生的
亚胺参与反应时,形成异构体双环壬二酮
IIIe和
IIIh以及
香豆酮VIIIa和
VIIIb,表明环化可能通过除[3,3]σ-重排之外的另一种途径进行。基于这些反应的反应过程和产物分布,提出了一个并行的反应途径,涉及
C-酰化-迈克尔加成。