σ-Inductive interaction through up to fourteen saturated C–C bonds
Abstract
Analysis of the NMR shifts of unsaturated carbon atoms in monounsaturated linear long-chain esters and acids, including new data from jojoba oil, rules out any explanation in terms of an ‘electric field effect’, but is semiquantitatively consistent with a ‘σ-inductive’ mechanism, having an attenuation factor of 1.75 per saturated C–C bond.