- Inter- and intramolecular O-H···π hydrogen bonding in the methanol-ethene complex and syn-7-norbornenol, probed by IR, 1H NMR and quantum chemistry
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The geometries and energies of syn-7-norbornenol (1) have been investigated with theoretical and experimental methods, while its epimer anti-7-norbornenol (2) has been investigated by theoretical methods only. It was found that 1 is intramolecularly hydrogen bonded and exists almost exclusively in its hydrogen bonded form, the Anti conformer. Compound 2, for which intramolecular hydrogen bonding is impossible, was found to exist as the Gauche conformer. A theoretical investigation of the model complex between methanol and ethene showed that the interaction energy is -3.1 ± 0.1 kcal mol-1 (estimated Hartree-Fock basis set limit plus correlation contribution, not including vibrational zero point energy). Electron correlation is essential in the evaluation of the interaction energy and also for the geometry of the complex. It was found that the potential energy surface around the minimum energy structure is flat, with an almost freely rotating methanol part.
- Bjerkeseth, Leif H.,Bakke, Jan M.,Uggerud, Einar
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- HEPATITIS C VIRUS INHIBITORS
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The present disclosure relates to compounds, compositions and methods for the treatment of hepatitis C virus (HCV) infection. Also disclosed are pharmaceutical compositions containing such compounds and methods for using these compounds in the treatment o
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Page/Page column 73-74
(2012/03/09)
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- TETRAHYDROPYRANYL CYCLOPENTYL TETRAHYDROISOQUINOLINE MODULATORS OF CHEMOKINE RECEPTOR ACTIVITY
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The present invention is directed to compounds of the formula I: I(wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, X, n and the dashed line are defined herein) which are useful as modulators of chemokine receptor activity. In particular, these compounds are useful as modulators of the chemokine receptor CCR-2.
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Page/Page column 142-143
(2010/02/07)
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- The twist angle approach to the stereoselectivity in reduction of ketones
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Semiempirical MO calculations show that the ?* orbital of the carbonyl carbon of asymmetric ketones deviates from orthogonality.These small deviations, measured by twist angles, are used to predict the configurations of the diastereoisomeric alcohols formed on reduction of the ketones with complex metal hydrides.The method is particularly suitable for predicting the changes in stereoselectivity when the carbonyl compound is substituted.This is illustrated by a number of examples of reduction of substituted rigid polycyclic ketones.It is proposed that a nucleophile approaches a carbonyl group preferentially from the side of obtuse angle with respect to the O-C bond.The twists incorporate the electronic nature of the substituent and help to understand the steric effect.Tha application of the twist angle approach to other reactions is briefly mentioned.
- Giddings, Michael R.,Hudec, John
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p. 459 - 467
(2007/10/02)
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- Synthesis of 3-Cyclopentenols by Alkoxy-Accelerated Vinylcyclopropane Rearrangement
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Lithium salts of 2-vinyl-1-cyclopropanols undergo vinylcyclopropane rearrangement at room temperature, providing an efficient method for the conversion of 1,3-dienes to functionalized cyclopentenes.
- Danheiser, Rick L.,Martinez-Davila, Carlos,Morin, John M.
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p. 1340 - 1341
(2007/10/02)
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