Stereoselective construction of an unprecedented 7-8 fused ring system in micrandilactone a by [3,3]-sigmatropic rearrangement.
The 7-8 bicyclic ring system of micrandilactone A (1) with the required stereochemistry and functional groups was constructed by a Bu3Al-promoted Claisen rearrangement. Computational studies indicated that the exocyclic vinyl ether undergoes a [3,3] sigmatropic process via a chairlike transition state to afford exclusively the Z-double bond in the newly generated 8-membered ring with a high level of chirality transfer.
Zhang
Yan-Dong
YD
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Shenzhen Graduate School, Peking University, Beijing 100871, China.
Ren
Wei-Wu
WW
Lan
Yu
Y
Xiao
Qing
Q
Wang
Kai
K
Xu
Jie
J
Chen
Jia-Hua
JH
Yang
Zhen
Z
D002384:Catalysis; D003500:Cyclization; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D032141:Schisandra / Q000737:chemistry*; D013237:Stereoisomerism; D014315:Triterpenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification
D007783:Lactones; D014315:Triterpenes; C476501:micrandilactone A; C521652:rubriflorin A