Synthesis of (−)‐3‐Carene‐2,5‐dione via Allylic Oxidation of (+)‐3‐Carene |
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Authors: | Xiaoling Sun Xiaoyan Zhao Ying Jiang Bochun Xu |
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Institution: | School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China |
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Abstract: | Activated carbon‐supported CuCl2 (CuCl2/AC) is a heterogeneous catalyst for the liquid‐phase selective allylic oxidation of (+)‐3‐carene with tert‐butyl hydroperoxide (TBHP) and O2 to produce (?)‐3‐carene‐2,5‐dione. The possible reaction mechanism and the effects of different factors on the allylic oxidation were investigated. The optimal conditions are as follows: reaction temperature, 45 °C; molar ratio of CuCl2 to (+)‐3‐carene, 1%; volume ratio of (+)‐3‐carene to TBHP, 1:3; and reaction time, 12 h. Under the optimal conditions, the conversion of (+)‐3‐carene reached 100%, whereas the selectivity for (?)‐3‐carene‐2,5‐dione reached 78%. The CuCl2/AC catalyst was characterized via X‐ray diffraction, and the chemical structure of the target compound was identified via infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, mass spectrometry, and optical analysis. |
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Keywords: | Activated carbon‐supported CuCl2 (− )‐3‐Carene‐2 5‐dione (+)‐3‐carene Allylic oxidation Mechanism |
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