ORGN 755 |
| We have found that [8]annulyne (cyclooctatrienyne) can undergo cyclic addition reactions with various olefins. This suggests that [8]annulenoazetidinones (Structure 1) might be produced by the reaction of [8]annulyne with isocyanates. When a mixture of N-ethyl isocyanate and monobromo[8]annulene (C8H7Br) is exposed to a solution of potassium tert-butoxide in hexamethylphosphoramide (HMPA) the C8H7Br undergoes a dehydrohalogenation reaction that generates [8]annulyne. Subsequently, a cycloaddition reaction takes place between [8]annulyne and N-ethyl isocyanate. However, the cycloaddition reaction does not generate the N-ethyl [8]annulenoazetidinone as predicted, but instead generates [8]annuleno-2,3-diethyl-2,3-dihydropyrazine-1,4-dione. Exposure of this solution to potassium metal yields a strong well-resolved EPR spectrum of the anion radical of this product. This reaction, along with the electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopic results, will be discussed. |
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Combinatorial, Parallel and Process Chemistry, Heterocycles, Aromatics, New Reactions and Methodology
8:00 PM-10:00 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |