¹³C nuclear magnetic resonance studies. 81. Conformational inversion barriers of some cis-decalins determined by ¹³C nuclear magnetic resonance

The 13Cmr spectra of 5β,10β-dimethyldecalin, 10β-decal-5β-ol, and 10β-methyldecal-5β-ol have been examined as a function of temperature to determine the barriers to conformational inversion. Lineshape fitting was employed to extract rate data from which the thermodynamic parameters governing the inversion processes were extracted. Comparison of these results with those obtained by molecular mechanics calculations indicates that the barrier for chair-twist to twist-twist interconversion dominates the conformational inversion profile.