In Problem 5.16 (Section 5.13) we saw that acid-catalyzed dehydration of 2,2 dimethylcyclohexanol afforded 1,2-dimethylcyclohexene. To explain this product we must write a mechanism for the reaction in which a methyl shift transforms a secondary carbocation to a tertiary one. Another product of the dehydration of 2,2-dimethylcyclohexanol is isopropylidenecyclopentane. Write a mechanism to rationalize its formation.

Problem 5.16
The alkene mixture obtained on dehydration of 2,2-dimethylcyclohexanol contains appreciable amounts of 1,2-dimethylcyclohexene. Give a mechanistic explanation for the formation of this product.

CH CH C(CH3)2 heat CH CH3 2,2-Dimethylcyclohexanol 1,2-Dimethylcyclohexee Isopropylidenecyclopentane