= Solution
\b[Methyl addition gives 1-methylcyclohexanol, whose acid-catalysed dehydration yields the shown 1-methylcyclohexene.] The methyl end of <methyllithium> attacks the cyclohexanone carbonyl carbon, and the C=O pi electrons move onto oxygen, giving a lithium alkoxide. Protonation gives the tertiary alcohol.
Protonate OH to make $\mathrm{OH_2^+}$, then cleave its C–O bond with both electrons going to departing water. A base removes a beta hydrogen from either adjacent ring methylene, and that C–H pair forms the C=C bond to the tertiary cationic centre. This <E1 elimination> regenerates the acid catalyst. The two adjacent ring positions are equivalent, and the displayed endocyclic alkene is more substituted than the possible exocyclic methylene alternative.
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