Mechanistic Insights into Ring-Opening and Decarboxylation of 2-Pyrones in Liquid Water and Tetrahydrofuran

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• 作者：Mei Chia ; M. Ali Haider ; Gerald Pollock ; III ; George A. Kraus ; Matthew Neurock ; James A. Dumesic
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：April 17, 2013
• 年：2013
• 卷：135
• 期：15
• 页码：5699-5708
• 全文大小：572K
• 年卷期：v.135,no.15(April 17, 2013)
• ISSN：1520-5126

文摘

2-Pyrones, such as triacetic acid lactone, are a promising class of biorenewable platform chemicals that provide access to an array of chemical products and intermediates. We illustrate through the combination of results from experimental studies and first-principle density functional theory calculations that key structural features dictate the mechanisms underlying ring-opening and decarboxylation of 2-pyrones, including the degree of ring saturation, the presence of C鈺怌 bonds at the C₄鈺怌₅ or C₅鈺怌₆ positions within the ring, as well as the presence of a 尾-keto group at the C₄ position. Our results demonstrate that 2-pyrones undergo a range of reactions unique to their structure, such as retro-Diels鈥揂lder reactions and nucleophilic addition of water. In addition, the reactivity of 2-pyrones and the final products formed is shown to depend on the solvent used and the acidity of the reaction environment. The mechanistic insights obtained here provide guidance for the selective conversion of 2-pyrones to targeted chemicals.