Total Synthesis of (±)-Deethylibophyllidine: Studies of a Fischer Indolization Route and a Successful Approach via a Pummerer Rearrangement/Thionium Ion-Mediated Indole Cyclization
作者:Josep Bonjoch、Juanlo Catena、Nativitat Valls
DOI:10.1021/jo960848z
日期:1996.1.1
derivatives, the regioselective Fischer indolization to obtain octahydropyrrolo[3,2-c]carbazoles, and the tandem process consisting of Pummerer rearrangement upon a beta-amino sulfoxide and thionium ion cyclization upon a beta-indole position of a 2,3-disubstituted indole to generate the quaternary spiro center. Attempts to effect the construction of the pentacyclic framework by means of Fischer indolization
描述了(+/-)-去乙基核糖胞苷的总合成,它是由4-(甲氧基苯基)乙胺以5%的总产率分八步进行的(方案6)。在顺序环化方面,该策略涉及以下操作:E-> DE-> ABDE-> ABCDE(方案1)。合成的关键步骤是通过酸处理二氢苯甲醚衍生物来立体选择性地形成八氢吲哚-6-酮,区域选择性费歇尔吲哚化反应以获得八氢吡咯并[3,2-c]咔唑,以及由β的Pummerer重排组成的串联过程-氨基亚砜和硫鎓离子在2,3-二取代的吲哚的β-吲哚位置上环化以生成季螺中心。试图通过八氢吡咯并尔的费歇尔吲哚化来实现五环骨架的构建[3,2,