Unsaturated monocyclic compounds. Part XLVIII. A study by nuclear magnetic resonance of the energy barrier for conformational interconversion in annulenes and dehydro-annulenes

Abstract

The temperature-dependent n.m.r. spectra of a number of annulenes and dehydro-annulenes have been correlated. By use of the observed values of Δν and the temperature of coalescence, Tc, an estimate for the free-energy barrier for interconversion of internal and external protons has been made.