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

作者：Chia Mei; Haider M Ali; Pollock Gerald III; Kraus George A; Neurock Matthew; Dumesic James A^*

来源：Journal of the American Chemical Society, 2013, 135(15): 5699-5708.

DOI：10.1021/ja312075r

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=C bonds at the C-4=C-5 or C-5=C-6 positions within the ring, as well as the presence of a beta-keto group at the C-4 position. Our results demonstrate that 2-pyrones undergo a range of reactions unique to their structure, such as retro-Diels-Alder 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.

• 出版日期2013-4-17