| Interaction / Compound | kJ/mol | kcal/mol |
|---|---|---|
| H : H eclipsing | 4.0 | 1.0 |
| H : CH3 eclipsing | 5.8 | 1.4 |
| CH3 : CH3 eclipsing | 11.0 | 2.6 |
| gauche butane | 3.8 | 0.9 |
| cyclopropane | 115 | 27.5 |
| cyclobutane | 110 | 26.3 |
| cyclopentane | 26.0 | 6.2 |
| cycloheptane | 26.2 | 6.3 |
| cyclooctane | 40.5 | 9.7 |
| Substituent(solvent) | kJ/mol | kcal/mol |
|---|---|---|
| -CH3 | 7.3 | 1.7 |
| -CH2CH3 | 7.5 | 1.8 |
| -CH(CH3)2 | 9.2 | 2.2 |
| -C(CH3)3 | 20 | 4.8 |
| phenyl | 11.7 | 2.8 |
| cyclohexyl | 9.2 | 2.2 |
| -CH=CH2 | 6.2 | 1.5 |
| -CCH, ethynyl | 2.1 | 0.5 |
| -CHO | 3.0 | 0.7 |
| -COCH3 | 5.1 | 1.2 |
| -CO2H | 5.9 | 1.4 |
| -CO2CH2CH3 | 5.0 | 1.2 |
| -Cl | 2.5 | 0.6 |
| -Br | 2.5 | 0.6 |
| -CN, cyano | 0.8 | 0.2 |
| -OH (cyclohexane) | 2.5 | 0.6 |
| -OH (isopropanol) | 4.0 | 1.0 |
| -OCH3 | 2.5 | 0.6 |
| -NH2 (toluene) | 5.2 | 1.2 |
| -NH2 (CH3OCH2CH2OH/H2O) | 7.1 | 1.7 |
| -NO2 | 4.8 | 1.1 |
a. Energy difference between axial and equatorial conformers.
b. Solvent specified when the increment is solvent dependent.
Data from Stereochemistry of Organic Compounds, E. L. Eliel and S. H. Wilen, John Wiley, New York, NY, 1994.