Synthesis of vinca alkaloids and related compounds. Part 108: Efficient convergent synthetic pathway to the ibophyllidine skeleton IV. First synthesis of (±)-18-hydroxy-20-epiibophyllidine
作者:Flórián Tóth、György Kalaus、Vajk Dániel Horváth、István Greiner、Mária Kajtár-Peredy、Ágnes Gömöry、László Hazai、Csaba Szántay
DOI:10.1016/j.tet.2007.05.105
日期:2007.8
The first total synthesis of the pentacyclic alkaloid (±)-18-hydroxy-20-epiibophyllidine was realized via an efficient preparation of the d-seco-pseudoaspidospermane molecule. The key step of the sequence involves an intramolecular [4+2] cycloaddition reaction of the dihydrosecodine intermediate, which was built up from the reaction of a tryptamine derivative with an aldehyde–ester. After full epimerization
五环生物碱(±)-18-羟基-20-表鬼臼核苷的第一个全合成是通过有效制备d- seco- pseudoaspidospermane分子而实现的。该序列的关键步骤涉及二氢secodine中间体的分子内[4 + 2]环加成反应,该反应是由色胺胺衍生物与醛酯的反应建立的。完全差向异构化后,四环酯的分子内N-烷基化得到五环化合物。后一种分子的还原得到标题化合物。