AbstractProton magnetic resonance spectrum of thujic acid was studid at 60MC. Ethylenic proton spectra appeared in the range of 2.35T‐4.89TThese are of interest from the point of view of structure determination. The proton spin‐spin coupling constants were determined to be 10.0cpsfor double‐bonded vicinal protons, and 6.8cpsfor single‐bonded vicinal protons. Two barely resolved quartets suggest the spin‐spin coupling between H1and H0for which the value was found to