Chemical Modification of Plant Alkaloids. 8. Stereocontrolled T-Reactions of (1R,5S,12S)-Tetrahydrocytisine Derivatives
作者:K. A. Krasnov、V. G. Kartsev、E. V. Dobrokhotova、E. K. Kultyshkina、N. Yu. Chernikova、P. V. Dorovatovskii、Ya. V. Zubavichus、V. N. Khrustalev
DOI:10.1007/s10600-018-2459-z
日期:2018.7
New heterocyclic quinolizidine systems were prepared from (1R,5S,12S)-tetrahydrocytisine. The synthetic scheme included arylation of tetrahydrocytisine by 2-fluoro-5-nitrobenzaldehyde and condensation of the resulting aldehyde with 1,3-dimethylbarbituric acid. The Knoevenagel intermediate obtained from the condensation was cyclized by a T-reaction to give two spirocyclic products as a derivative with the lupanine skeleton and its regioisomer with the 11,15-diazapentacyclo[11.7.1.02,11.05,10.015,20]heneicosane skeleton. The cyclization occurred highly stereoselectively. The structures of the products were proven using NMR and X-ray crystal structure analyses.
由 (1R,5S,12S)- 四氢胞嘧啶制备了新的杂环喹嗪系统。合成方案包括用 2-氟-5-硝基苯甲醛对四氢胞嘧啶进行芳基化反应,并将生成的醛与 1,3-二甲基巴比妥酸缩合。通过 T 反应将缩合得到的 Knoevenagel 中间体环化,得到两种螺环产物,一种是以羽扇豆碱为骨架的衍生物,另一种是以 11,15-二氮杂五环[11.7.1.02,11.05,10.015,20]heneicosane 为骨架的区域异构体。环化过程具有高度的立体选择性。利用核磁共振和 X 射线晶体结构分析证明了产物的结构。