Coniothyrione: anatomy of a structure revision |
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| Authors: | Gary E Martin Alexei V Buevich Mikhail Reibarkh Sheo B Singh John G Ondeyka R Thomas Williamson |
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| Institution: | 1. Merck Research Laboratories Discovery and Preclinical Sciences – Global Chemistry, Process and Analytical Chemistry, Structure Elucidation Group Summit, , NJ, 07065 USA;2. Merck Research Laboratories Discovery and Preclinical Sciences – Global Chemistry, Process and Analytical Chemistry, Structure Elucidation Group, , Kenilworth, NJ, 07033 USA;3. Merck Research Laboratories Discovery and Preclinical Sciences – Global Chemistry, Process and Analytical Chemistry, Structure Elucidation Group, , Rahway, NJ, 07065 USA;4. Merck Research Laboratories Discovery and Preclinical Sciences – Global, Chemistry, Medicinal Chemistry, , Rahway, NJ, 07065 USA |
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| Abstract: | Coniothyrione is a xanthone‐derived antibiotic reported several years ago by researchers at Merck & Co. Inc. Revision of the position of the chloro substitution was recently proposed on the basis of empirical reinterpretation of the carbon chemical shift data and a hypothetical biosynthetic argument without the acquisition of any new spectral data to support the postulated change in substituent location. The originally published HMBC data lead to an equivocal assignment of the structure and do not provide a solid basis of support for either structure. Neural network 13C chemical shift calculations and density functional theory calculations also led to undifferentiated structures. Definitive confirmation of the structure of coniothyrione based on the acquisition and interpretation of 1,1‐ADEQUATE and inverted 1JCC 1,n‐ADEQUATE data is now reported. Copyright © 2013 John Wiley & Sons, Ltd. |
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| Keywords: | NMR Coniothyrione ADEQUATE HSQMBC DFT covariance antisense coniothyrium cerealis |
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