Absolute Configuration of 7,8-seco-7,8-Oxacassane Diterpenoids from Acacia schaffneri
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- 作者：J. Jesu虂s Manri虂quez-Torres ; J. Marti虂n Torres-Valencia ; Mario A. Go虂mez-Hurtado ; Virginia Motilva ; Sofi虂a Garci虂a-Maurin虄o ; Javier A虂vila ; Elena Talero ; Carlos M. Cerda-Garci虂a-Rojas ; Pedro Joseph-Nathan
- 刊名：Journal of Natural Products
- 出版年：2011
- 出版时间：September 23, 2011
- 年：2011
- 卷：74
- 期：9
- 页码：1946-1951
- 全文大小：845K
- 年卷期：v.74,no.9(September 23, 2011)
- ISSN：1520-6025
文摘
Chemical investigations of Acacia schaffneri led to the isolation of the new diterpenoid (5S,7R,8R,9R,10S)-(鈭?-7,8-seco-7,8-oxacassa-13,15-diene-7,17-diol (1), together with the known (5S,7R,8R,9R,10S)-(鈭?-7,8-seco-7,8-oxacassa-13,15-dien-7-ol-17-al (2) and (5S,7R,8R,9R,10S)-(鈭?-7,8-seco-7,8-oxacassa-13,15-dien-7-ol (3). Compounds 2 and 3 were analyzed by single-crystal X-ray diffraction, while the structure of 1 was determined by 1D and 2D NMR experiments and by chemical correlation with 2. Oxidation of 3 afforded conformationally restricted (5S,8R,9R,10S)-(鈭?-8-hydroxy-7,8-seco-cassa-13,15-dien-7-oic acid 蔚-lactone (4), which was studied by vibrational circular dichroism spectroscopy. Comparison of the experimental VCD spectrum of 4 with the DFT//B3PW91/DGDZVP2 calculated spectrum assigned for the first time the absolute configuration of these seco-oxacassane diterpenes.