92406-81-0Relevant academic research and scientific papers
Permethylcyclohexane
Fitjer, Lutz,Scheuermann, Hans-Joerg,Wehle, Detlef
, p. 2329 - 2332 (1984)
Permethylcyclohexane 2 has been synthesized and investigated by dynamic NMR spectroscopy.An unexpectedly low barrier (Γ333(act)= 70.0 kJ/mol) of its chair-to-chair interconversion was found.
Sterically Crowded Cyclohexanes, 5. Synthesis, Conformation and Dynamics of 4,4,5,5,6,6,7,7,8,8-Decamethylspirooctane and Dodecamethylcyclohexane
Wehle, Detlef,Scheuermann, Hans-Joerg,Fitjer, Lutz
, p. 3127 - 3140 (2007/10/02)
Synthesis, conformation and dynamics of the title compounds 3 and 4 are described.Ketones 5, m = 2 and 5, m = 3 were first transformed to spiranes 8, m = 2 and 8, m = 3 (= 3), respectively.Catalytic hydrogenation then yielded 9 and 10, and 4 and 11, respectively.Both 3 and 4 adopt a chair conformation.The activation parameters of the chair-to-chair interconversion of 3 were determined by analysis of the 13C DNMR spectra using the coalescence method, those of 4 by bandshape analysis of the 1H DNMR spectra.The results were as follows: 3: ΔG%373 = 16.3 +/- 0.5 kcal/mol; 4: ΔH% = 15.6 +/- 0.2 kcal/mol, ΔS% = -5.6 +/- 0.6 cal/mol grd, ΔG%298 = 17.3 +/- 0.4 kcal/mol.The unexpectedly low inversion barriers of 3 and 4 are discussed.
