Fluorine and proton nmr studies of the conformations of 4,4-difluorocyclohexanol and its benzoate

Fluorine substitution into a polar flexible molecule may be expected to significantly alter the conformational equilibria for that molecule because of electrostatic (or other) interactions between polar substituents and the fluorine atoms. Therefore, the “fluorine-labeling technique” which has been used successfully in conformational studies of hydrocarbons (4.5). should not be extended to polar flexible molecules without taking account of the interactions introduced by the fluorine atoms and their effect on the conformational energies. We report here studies of conformational equilibria by fluorine and proton nmr directed toward evaluation of the transannular interactions introduced when a 4,4-difluoro group is substituted into cyclohexanol (and other related polar flexible molecules)