Stereochemical investigations. XL. Conformational characteristics of 2-substituted 1,1-difluorocyclohexanes. Disappearance of the gauche effect
The conformational equilibria in the series of 2-substituted 1,1-difluorocyclohexanes were investigated by comparison of the integral intensities of the signals of the conformers in the low-temperature /sup 19/F NMR and PMR spectra and from the averaged width of the signal for the methine proton ion the PMR spectra. It was found that the equilibrium is displaced toward the axial conformer compared with the corresponding monosubstituted cyclohexanes, and this was explained on the basis of dipole-dipole repulsion in the equatorial conformer. The structural characteristics of the 1,1,2-trisubstituted cyclohexanes prevent the appearance of the quantum-mechanical effect which stabilizes the gauche arrangement of the strongly electronegative substituents.
- Research Organization:
- M.V. Lomonosov Moscow State Univ. (USSR)
- OSTI ID:
- 5887803
- Journal Information:
- J. Org. Chem. USSR (Engl. Transl.); (United States), Journal Name: J. Org. Chem. USSR (Engl. Transl.); (United States) Vol. 24:7; ISSN JOCYA
- Country of Publication:
- United States
- Language:
- English
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400201* -- Chemical & Physicochemical Properties
ALKANES
ANGULAR MOMENTUM
ATOMIC MODELS
CHEMICAL SHIFT
CONFORMATIONAL CHANGES
COUPLING
COUPLING CONSTANTS
CYCLOALKANES
CYCLOHEXANE
ELECTRON DENSITY
ELECTRONEGATIVITY
ELECTRONIC STRUCTURE
EQUILIBRIUM
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE 19
FLUORINE ISOTOPES
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
INTERMEDIATE COUPLING
ISOTOPES
J-J COUPLING
LIGHT NUCLEI
LINE WIDTHS
MATHEMATICAL MODELS
MOLECULAR MODELS
MOLECULAR STRUCTURE
MULTIPLETS
NMR SPECTRA
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PARTICLE PROPERTIES
SPECTRA
SPIN
STABLE ISOTOPES
STEREOCHEMISTRY
STRUCTURAL CHEMICAL ANALYSIS