Chapter 3, Problem 44P

The heats of combustion of the more and less stable stereoisomers of the $1,2-,1,3-,$

and $\text{1,4-dimethylcyclohexanes}$ are given here. The values are higher for the $\text{1,2-dimethylcyclohexanes}$ than for the $1,3-$ and $1,4-$ isomers. Suggest an explanation.

Dimethylcyclohexane $1,2$ $1,3$ $1,4$

Heats of combustion (kJ/mol):

More stable stereoisomer $5217$ $5212$ $5212$

Less stable stereoisomer $5223$ $5219$ $5219$

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