The nuclear magnetic resonance method for determining conformational preferences in substituted cyclohexanes. Allowance for ring deformation
Abstract
The effect of remote alkyl substituents on the chemical shifts of methine protons in cyclohexyl compounds probably arises from changes in the polarisability of the ring due to deformation (and hence the inductive effect of the C-1 substituent), and not only from the accompanying changes in anisotropic shielding.