title: A bio-inspired synthetic route to the core ring systems of Spiraea atisine-type diterpenoid alkaloids and related diterpenes.
abstract: A bio-inspired synthetic strategy for the efficient construction of the structurally complex azapentacyclic ABEFG ring systems of Spiraea atisine-type diterpenoid alkaloids bearing a characteristic internal carbinolamine ether linkage between C(7) and C(20) has been successfully developed. The highly bridged azapentacyclic core structure was constructed rapidly from a readily prepared trans-6,6-bicyclic AB ring precursor through a 14-step sequence. Highlights of the synthesis include a straightforward formal lactone migration from the tricyclic γ-lactone unit of naturally occurring spiramilactone E, and an efficient biomimetic synthesis of the azapentacyclic ABEFG ring systems of spiramines C and D from the corresponding tetracyclic subunits of spiraminol and spiramilactone B.
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China. liangxu@scu.edu.cn.
authors.forename: Dai-Hui
authors.initials: DH
authors.lastname: Tang
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China. liangxu@scu.edu.cn.
authors.forename: Ding
authors.initials: D
authors.lastname: Ma
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China. liangxu@scu.edu.cn.
authors.forename: Hang
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China. liangxu@scu.edu.cn.
authors.forename: Yong-Li
authors.initials: YL
authors.lastname: Li
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China. liangxu@scu.edu.cn and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D031992:Spiraea / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D004224:Diterpenes