When 1-methylcyclohexanol is dehydrated using concentrated sulfuric acid, the major product formed is 1-methylcyclohexene. This is because the reaction proceeds via an E1 mechanism, in which a proton is first abstracted from the alcohol group to form a carbocation intermediate. This carbocation can then undergo rearrangement to form a more stable carbocation, which then loses a proton to form the alkene. In this case, the most stable carbocation is the one formed by the rearrangement of the methyl group to the allylic position.

Minor Product: 3-Methylcyclohexene

A minor product of the dehydration of 1-methylcyclohexanol is 3-methylcyclohexene. This is formed via a competing E2 mechanism, in which a proton is abstracted from the alcohol group at the same time as the hydroxyl group is lost. This results in the formation of a two-carbon anion, which can then protonate to form the alkene. In this case, the two-carbon anion can either protonate to form 1-methylcyclohexene or 3-methylcyclohexene.

The ratio of 1-methylcyclohexene to 3-methylcyclohexene produced in the dehydration of 1-methylcyclohexanol depends on the reaction conditions. In general, higher temperatures and longer reaction times favor the formation of the more stable 1-methylcyclohexene.