2,2-Dimethylcyclohexanol is heated with conc. $\mathrm{H}{}_2\mathrm{SO}{}_4$. The major alkene is:

The secondary cation at C1 has a quaternary neighbour (C2), so a 1,2-methyl shift gives the tertiary cation at C2 (C1 now carries H and $\mathrm{CH}{}_3$). Loss of the C1 proton gives the tetrasubstituted alkene 1,2-dimethylcyclohexene, the most stable, as the major product. Loss from C3 would give the less substituted 1,6-dimethylcyclohexene.