Facile construction of the pentacyclic framework of subincanadine B. Synthesis of 20-deethylenylated subincanadine B and 19,20-dihydrosubincanadine B.
[reaction: see text] 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.
Liu
Yanqin
Y
Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai.
Luo
Shengjun
S
Fu
Xingnian
X
Fang
Fang
F
Zhuang
Zeyang
Z
Xiong
Wanting
W
Jia
Xueshun
X
Zhai
Hongbin
H
D005030:Ethylenes / Q000737:chemistry*; D026121:Indole Alkaloids / Q000138:chemical synthesis*
D005030:Ethylenes; D026121:Indole Alkaloids; C472461:subincanadine B; C036216:ethylene