Free Energy Differences for Cyclohexyl Substituents
 
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
Michigan State University

 

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.