| Substituent Group |
Free Energy
ΔG º (axial–equatorial) |
|---|---|
|
CH3 |
1.74 kcal mol-1 |
|
C2H5 |
1.8 |
|
(CH3)2CH |
2.2 |
|
(CH3)3C |
4.7 |
|
CF3 |
2.4 |
|
C6H5 |
2.8 |
|
CH2=CH |
1.6 |
|
HC≡C |
0.45 |
|
CN |
0.2 |
|
CHO |
0.7 |
|
COCH3 |
1.2 |
|
CO2H |
1.4 |
|
CO2 Na |
2.0 |
|
CO2CH3 |
1.3 |
|
COCl |
1.3 |
|
F |
0.3 |
|
Cl |
0.6 |
|
Br |
0.6 |
|
I |
0.55 |
|
OH |
0.6 - 1.0 |
|
OCH3 |
0.65 |
|
OCOCH3 |
0.75 |
|
OSI(CH3)3 |
0.7 |
|
SH |
1.2 |
|
NH2 |
1.3 - 1.7 |
|
N(CH3)2 |
2.0 |
|
N3 |
0.5 |
|
NO2 |
1.1 |
|
Si(CH3)3 |
2.5 |
Organic Chemistry
|
These "Conformational Energies" or "A values" are -ΔG° 's for axial/equatorial equilibria of substituted cyclohexanes. The data in this table are averaged from several different sources. For a more precise and extensive compilation see: E.L.Eliel and S.H.Wilen, Stereochemistry of Organic Compounds, 1994.