Efficient Formal Total Synthesis of Physostigmine and Physovenine: Conformational Analysis of Key Intermediates
作者:Martha S. Morales-Ríos、Norma F. Santos-Sánchez、Pedro Joseph-Nathan
DOI:10.1021/np010475j
日期:2002.2.1
An efficient route for the formal total synthesis of physostigmine (1) and physovenine (2), alkaloids from 5-methoxyindole-3-acetonitrile, through a Grignard reagent 1,4-addition, is described. 2-Hydroxyindolenine 5, the key advanced intermediate for the synthetic targets, was converted either to esermethole (12) via a high-yielding (28%) seven-step sequence or to the C-ring oxygenated analogue 15
描述了通过格氏试剂1,4-加成从5-甲氧基吲哚-3-乙腈中生物碱类毒扁豆碱(1)和植物毒气(2)的形式的正式总合成的有效途径。合成目标物的关键高级中间体2-羟基吲哚啉5通过高产率(28%)的七步序列转化为乙二胺(12)或通过五步序列转化为C环氧化类似物15和23%的总产量。(1)乙二胺(12)和呋喃二苯胺13和15的1 H NMR和分子模型分析用于反卷积加权时间平均邻域偶合常数,以在CD(2)Cl(2)溶剂中提供确定的溶液状态构象偏爱。