Synthesis and Structure of Tetrahydro-4,7-ethanoisobenzofuran-1,3-dione Derivative |
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Authors: | Mingfeng Fang Chunmeng Pan Song Lu Zhongxiang Lin Guo-Yuan Lu |
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Institution: | 1. College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China 2. Department of Chemistry, Nanjing University, Nanjing, Jiangsu 210093, China |
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Abstract: | (1R,2R,3S,4R,7R)‐7‐Isopropyl‐6‐methylbicyclo2.2.2]oct‐5‐ene‐2,3‐dicarboxylic acid anhydride (tetrahydro‐4,7‐ethanoisobenzofuran‐1,3‐dione derivative) adduct 2 was prepared via the isomerization of α‐pinene and β‐pinene in turpentine followed by the Diels‐Alder cycloaddition with maleic anhydride in the presence of phosphoric acid/iodine catalysis. The molecular structure of adduct 2 was characterized by IR, 1H NMR, 13C NMR, 1H‐1H COSY, DEPT, HSQC, HMBC, 2D NOESY and MS spectra. The single crystal X‐ray crystallographic analysis of adduct 2 was performed, and the X‐ray powder diffractive spectrum of the sample adduct 2 is consistent with the diffractive spectrum calculated from the single crystal data. Therefore the structure and stereochemistry of adduct 2 was established based on extensive spectral data and single crystal X‐ray analysis. |
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Keywords: | turpentine NMR spectra configuration crystal structure Diels-Alder reaction |
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