Influence of methyl substituents on the chemical shift of the ring protons in mono‐, di‐ and trimethylcyclohexanes a 300 MHz study of the ¹H NMR spectrum of <i>cis</i>‐1,3‐dimethylcyclohexane

Abstract

Abstract From a 300 MHz spectral study of mono‐to trisubstituted cyclohexanes, allowing a re‐examination of some of their 1 H NMR spectral parameters, it is shown that it is possible to predict with reasonable accuracy the shifts (in CCl 4 ) of the ring protons. A substantial feature in this is the validity of the (questioned) additivity of multiple effects. It is also shown that with respect to shift alterations, equatorial ring protons behave anomalously, which cannot be explained by any existing theoretical model.