Facile Construction of the Pentacyclic Framework of Subincanadine B. Synthesis of 20-Deethylenylated Subincanadine B and 19,20-Dihydrosubincanadine B
datasetposted on 05.01.2006, 00:00 by Yanqin Liu, Shengjun Luo, Xingnian Fu, Fang, Zeyang Zhuang, Wanting Xiong, Xueshun Jia, Hongbin Zhai
We describe a facile approach for effectively constructing the pentacyclic framework of subincanadine B. The seven-step assembly of tetracyclic ketone 14 featured Michael addition, Pictet−Spengler cyclization, and Dieckmann condensation. From this key ketone intermediate, two analogues of subincanadine B, i.e., 20-deethylenylated subincanadine B (27) and 19,20-dihydrosubincanadine B (31), were synthesized in four steps, respectively.