Studies in nuclear magnetic resonance—XII: Complete analysis of the proton spectra of tert‐butylcyohexane‐3,3,4,4,5,5‐d₆ and ‐3,3,5,5‐d₄

Accurate parameters for the two title compounds have been obtained by the aid of a spectral subtraction technique in conjunction with analysis by LAOCN3. It is observed that J 1eq, 6eq and J 1ax, 2ax are abnormally large and small, respectively, and the significance of these and other coupling constants are discussed in terms of the probable geometry of tert ‐butylcyclohexane. The tert ‐butyl group affects the chemical shifts of the 4‐protons, indicating that tert ‐butylcyclohexyl derivatives are poor models for fixed conformers of monosubstituted cyclohexanes. The deuterium isotope effects on proton chemical shifts appear to be influenced by the same factors as proton‐proton coupling constants.