- Thermodynamic, spectroscopic, and density functional theory studies of allyl aryl and prop-1-enyl aryl ethers. Part 1. Thermodynamic data of isomerization
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A chemical equilibration study of the relative thermodynamic stabilities of seventy isomeric allyl aryl ethers (a) and (Z)-prop-1-enyl aryl ethers (b) in DMSO solution has been carried out. From the variation of the equilibrium constant with temperature the Gibbs energies, enthalpies, and entropies of isomerization at 298.15 K have been evaluated. Because of their low enthalpies, the (Z)-prop-1-enyl aryl ethers are strongly favored at equilibrium, the Gibbs energies of the a→b isomerization ranging from -12 to -23 kJ mol-1. The entropy contribution is negligible in most reactions, but occasionally small positive values less than +10 J K-1 mol-1 of the entropy of isomerization are found. The equilibration studies were also extended to involve two pairs of related isomeric ethers with a Me substituent on C(2) of the olefinic bond. The Me substituent was found to increase the relative thermodynamic stability of the allylic ethers by ca. 3.4 kJ mol-1.
- Taskinen, Esko
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p. 1824 - 1834
(2007/10/03)
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- Skin sensitization to eugenol and isoeugenol in mice: Possible metabolic pathways involving ortho-quinone and quinone methide intermediates
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With the aim of providing further mechanistic insights into the mode of action of eugenol (4-allyl-2-methoxyphenol) and isoeugenol (4-propenyl-2- methoxyphenol), we have synthesized two series of modified compounds which were tested in the mouse local lym
- Bertrand, Franck,Basketter, David A.,Roberts, David W.,Lepoittevin, Jean-Pierre
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p. 335 - 343
(2007/10/03)
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