Nuclear magnetic resonance studies of 1,3‐butadienes. IX—The 1H spectra of isoprene and related compounds

Full analyses of the five‐spin 1H n.m.r. spectra for the diene protons of isoprene, ethylbutadiene and β‐myrcene under conditions of decoupling the sidechain α‐protons are reported. The data are discussed in terms of spin–spin coupling mechanism and molecular conformation. The fully‐coupled spectra of the compounds were also examined and coupling information obtained.