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