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Synthesis of (−)‐3‐Carene‐2,5‐dione via Allylic Oxidation of (+)‐3‐Carene
Author(s) -
Sun Xiaoling,
Zhao Xiaoyan,
Jiang Ying,
Xu Bochun
Publication year - 2013
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201100694
Subject(s) - chemistry , allylic rearrangement , catalysis , molar ratio , selectivity , infrared spectroscopy , mass spectrometry , spectroscopy , medicinal chemistry , nuclear chemistry , organic chemistry , chromatography , physics , quantum mechanics
Activated carbon‐supported CuCl 2 (CuCl 2 /AC) is a heterogeneous catalyst for the liquid‐phase selective allylic oxidation of (+)‐3‐carene with tert‐butyl hydroperoxide (TBHP) and O 2 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 CuCl 2 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 CuCl 2 /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.