The relevant effect of an intramolecular hydrogen bond on the conformational equilibrium of cis-3-methoxycyclohexanol compared to trans-3-methoxycyclohexanol and cis-1,3-dimethoxycyclohexane.

  title={The relevant effect of an intramolecular hydrogen bond on the conformational equilibrium of cis-3-methoxycyclohexanol compared to trans-3-methoxycyclohexanol and cis-1,3-dimethoxycyclohexane.},
  author={Paulo R. de Oliveira and Roberto Rittner},
  journal={Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy},
  volume={61 8},
1H NMR data show that an increase in the concentration of cis-3-methoxycyclohexanol (cis-3-MCH) shifts the conformational equilibrium from the 1aa conformer, stabilized by an intramolecular hydrogen bond (IAHB), to the 1ee conformer [X(ee) = 44% (at 0.05 molL(-1)) to 59% (at 0.40 molL(-1)), in CCl4], which forms intermolecular hydrogen bonds (IEHB), as confirmed by IR data. The percentage of 1ee conformer increases with the solvent polarity, from 33% (DeltaG(ee-aa) = 1.72 kJmol(-1)) in… Expand
The subtle electronic effects of alkyl groups on the conformational equilibria and intramolecular hydrogen-bond strength in cis-3-alkoxycyclohexanols.
The Deltanu values, obtained by IR spectra, indicated that increasing the size of the OR group, R=CH3, CH2CH2CH3 and CH(CH3)2, increases the IAHB strength, due to an increase in the inductive effect of R group, which makes the oxygen lone pairs more available for an I AHB with OH group, in opposition to the steric effect. Expand
Influence of OH⋯N and NH⋯O inter- and intramolecular hydrogen bonds in the conformational equilibrium of some 1,3-disubstituted cyclohexanes through NMR spectroscopy and theoretical calculations.
The results indicate for the first time that the IAHB NH⋯O is not strong enough to stabilize the diaxial conformer of these compounds and that the conformation equilibria of the cis isomers of compounds ACOL and MCOL are influenced only by the I AHB OH⋰N. Expand
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Data showed that the diequatorial conformer is predominant in the conformational equilibrium of the compounds studied at low temperature, but compounds 6 and 7 constitute an exception, since they are almost equally populated by ee and aa at room temperature, due to stabilization of their aa conformer by an intramolecular hydrogen bond. Expand
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IR gas-phase and quantum chemical data that characterize the intramolecular hydrogen bonds in a series of 2-hydroxybenzoyl compounds (Ph(OH)(COY):  Y = Cl, OH, SH, OCH3, SCH3, H, CH3, Ph,Expand
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