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.

@article{deOliveira2005TheRE,
  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},
  year={2005},
  volume={61 8},
  pages={
          1737-45
        }
}
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.
TLDR
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TLDR
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References

SHOWING 1-10 OF 33 REFERENCES
Conformational analysis. Part 21. Conformational isomerism in cis-cyclohexane-1,3-diol
cis-Cyclohexane-1,3-diol (CHD) has been isolated from a cis/trans isomeric mixture by first synthesizing the cyclic acetal 2,4-dioxabicyclo[3.3.1]nonane (D). The 1H NMR spectra of CHD, D, cis-andExpand
Conformational analysis. Part 28. OH⋯F hydrogen bonding and the conformation of trans-2-fluorocyclohexanol
The 1H and 13C NMR spectra of trans-2-fluorocyclohexanol 1 and the methyl ether 2 have been obtained in a variety of solvents and temperatures. From the low-temperature spectra the proportions of theExpand
Halogenated six-membered rings: a theoretical approach for substituent effects in conformational analysis
Abstract Studies on the conformational equilibria of a series of dihalosubstituted cyclohexanes ( I ) and halocyclohexanones ( II ) are reported. Theoretical calculations using the B3LYP method andExpand
Conformational Studies in the Cyclohexane Series. 1. Experimental and Computational Investigation of Methyl, Ethyl, Isopropyl, and tert-Butylcyclohexanes.
TLDR
A novel experimental approach to evaluation of highly biased conformational equilibria is described that obviates the need to measure large axial/equatorial isomer ratios directly in order to determine the equilibrium constant. Expand
Intramolecular O-H··N hydrogen bonds in 2-hydroxybenzaldimine compounds: Spectroscopic and quantum chemical investigations
SummarySpectroscopic and quantum chemical data that characterize the intramolecular hydrogen bonds in a series of 2-hydroxybenzaldimine compounds (Ph(OH)(CH=N-R);R=-NH(Ph), -OH,-OCH3, -NH2, -Ph,Expand
Conformationally controlled intramolecular charge transfer complexes.
TLDR
Trans-1-acceptor-2-donor-substituted cyclohexanes, as well as their 4- (or 5-)methyl-subStituted homologues, have been prepared and are shown to form intramolecular charge-transfer (donor) complexes that are turned on and off by the chair-chair interconversion of the cyclo hexane ring. Expand
Hydrogen bonding and tautomerism in 3-substituted β-thioxoketones: an ab initio molecular orbital study
The molecular geometry of some 3-substituted β-thioxoketones (R = CN, OH, F, CH3) and of 3-methyl-4-mercaptopent-3-en-2-one (6) has been fully optimised by ab initio molecular orbital calculationsExpand
Intramolecular Hydrogen Bonding in 2-Hydroxybenzoyl Compounds: Infrared Spectra and Quantum Chemical Calculations
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
Large perturbations of long-range nJ(1H,1H) and nJ(1H,19F) by the intramolecular hydrogen bonds in 2-mercaptobenzaldehyde, salicylaldehyde, and some derivatives. Reference structures for intramolecular hydrogen bonds
Precise 1H nuclear magnetic resonance spectral parameters are reported for salicyladehyde and its 3-fluoro and 5-fluoro derivatives in nonpolar solutions. Such data are also given for the 2-mercapto,Expand
Quantum-chemical studies of hydrogen bonding involving thioxoketones, thienols, thioformaldehyde and hydrogen sulfide with specific reference to the strength of intramolecular hydrogen bonds
The results of ab initio quantum-chemical calculations are reported for rotamers of S(CH)3OH (thioxoketone) and HS(CH)3O (thienol), several complexes of these with H2O and H2S as well as a range ofExpand
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