Trans-1,2-Dimethoxycyclohexane conformations

The positions of the equilibria between the di-equatorial and di-axial conformers of trans-1,2-dimethoxycyclohexane and trans-2-methoxy-cyclohexanol were determined accurately by 13C NMR spectroscopy at —80 °C using a number of solvents ranging from non-polar pentane to the strongly polar methanol (cf. Table IV) (96AJC379). The di-equatorial conformer is preferred under all conditions but the extent increases... 

The solvent dependence of the conformational equilibria of trans-1,4-dimethoxycyclohexane and tra s,cA-l-Me-3,5-dimethoxycyclohexane was studied by low temperature ll NMR spectroscopy (90JCR(S)152) (cf. Table VI). The conformational equilibria of trans-1 -acceptor-2-donor-substituted cyclohexanes 10ee=10aa were studied with respect to intramolecular charge-transfer (donor-acceptor) complexes (CT) in the di-equatorial conformation (02JOC6938) the CT absorptions and the... 

This contrasts with the two conformers of trans-1,4-dimethoxycyclohexane (diaxial or diequatorial), which rapidly interconvert at room temperature without breaking any bonds. 

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