TY - JOUR
T1 - Biomimetic synthesis of xuxuarines Eα and Eβ
T2 - Structure revision of Rzedowskia bistriterpenoids
AU - Jacobsen, Neil E.
AU - Wijeratne, E. M.Kithsiri
AU - Corsino, Joaquim
AU - Furlan, Maysa
AU - Bolzani, Vanderlan da S.
AU - Gunatilaka, A. A.Leslie
N1 - Funding Information:
We thank the University of Arizona College of Agriculture and Life Sciences for financial support, CAPES/PICDT (Brazil) for a graduate fellowship (to J.C.), Alex A. Jeller for the initial supply of pristimerin for optimization of reaction conditions, and Dr. Katalin Kövér, University of Debrecen, Hungary, for the gradient-selected phase-sensitive HMBC pulse sequence.
PY - 2008/2/15
Y1 - 2008/2/15
N2 - Reaction of pristimerin with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted in a biomimetic-type coupling leading to xuxuarines Eα and Eβ and not the previously reported Rzedowskia bistriterpenoids I and II suggesting that the structures proposed for these natural products need revision. A product obtained in this reaction by an unusual Diels-Alder addition followed by retro-Diels-Alder-type elimination was characterized as pristimerin dicyanophenalenedione. Complete 1H, and 13C NMR spectral assignments of xuxuarines Eα and Eβ have been made by the application of 1D and 2D NMR techniques.
AB - Reaction of pristimerin with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted in a biomimetic-type coupling leading to xuxuarines Eα and Eβ and not the previously reported Rzedowskia bistriterpenoids I and II suggesting that the structures proposed for these natural products need revision. A product obtained in this reaction by an unusual Diels-Alder addition followed by retro-Diels-Alder-type elimination was characterized as pristimerin dicyanophenalenedione. Complete 1H, and 13C NMR spectral assignments of xuxuarines Eα and Eβ have been made by the application of 1D and 2D NMR techniques.
KW - Biomimetic synthesis
KW - Biscelastroloids
KW - DDQ oxidation
KW - Rzedowskia bistriterpenoids
KW - Xuxuarine Eα
KW - Xuxuarine Eβ
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U2 - 10.1016/j.bmc.2007.11.008
DO - 10.1016/j.bmc.2007.11.008
M3 - Article
C2 - 18055208
AN - SCOPUS:38949181549
SN - 0968-0896
VL - 16
SP - 1884
EP - 1889
JO - Bioorganic and Medicinal Chemistry
JF - Bioorganic and Medicinal Chemistry
IS - 4
ER -