One of the chair conformations of cis-1-bromo-3-methylcyclohexane is more stable than the other by 14.0 kJ/mol. Use this, and the table below, to estimate the energy cost of a 1,3-diaxial interaction between a bromine atom and a methyl group.
1,3-Diaxial Strain Energies for Monosubstituted Cyclohexanes
Substituent kJ/mol Substituent kJ/mol
-CN, cyano 0.4
-NH2 -COOH 2.95
-F 0.5
-CH=CH, ethynyl 0.85
-CH=CH2 3.55
-I 0.95
-CH3 3.64
-Cl 1.1
-CH2CH3 3.65
-Br 1.2
-CH(CH3)2 4.5
-OH 1.95
-C(CH3)3 10.5
-C6H5 6.3
(Round your answer to one decimal place.)