Carbon‐13 chemical shifts of monosubstituted cyclohexanes

The carbon‐13 chemical shifts of monosubstituted cyclohexane derivatives are compared with those of aliphatic compounds. The polar substituents exert a similar influence on the α‐, β‐ and γ‐carbons in both series of compounds. The δ‐effect is shown to be characteristic mainly to the cyclic compounds, however. The appearance of a δ‐effect is discussed as a possible consequence of electron delocalization in alicyclic molecules. A correlation of these δ‐effects with inductive parameters of the substituents is presented.