The correct answer is: D. mixture of cis and trans-2-methylcyclohexanol.
The oxymercuration-demercuration reaction is a two-step reaction that converts an alkene into a corresponding alcohol. The first step is the addition of mercuric acetate to the alkene, which forms a mercurinium ion. The second step is the addition of water to the mercurinium ion, which forms the alcohol and regenerates the mercuric acetate.
In the case of t-methylcyclohexene, the oxymercuration-demercuration reaction will produce a mixture of cis-2-methylcyclohexanol and trans-2-methylcyclohexanol. This is because the mercurinium ion can attack the alkene from either side, resulting in the formation of two different products.
The following is a diagram of the oxymercuration-demercuration reaction of t-methylcyclohexene:
The first step of the reaction is the addition of mercuric acetate to the alkene. This forms a mercurinium ion, which is a three-membered ring with a mercury atom in the center. The mercurinium ion is a very reactive intermediate, and it can attack any nucleophile. In this case, the nucleophile is water.
The second step of the reaction is the addition of water to the mercurinium ion. This forms the alcohol and regenerates the mercuric acetate. The alcohol can be either cis-2-methylcyclohexanol or trans-2-methylcyclohexanol, depending on which side the water attacks the mercurinium ion.
The following is a diagram of the mercurinium ion:
The mercurinium ion is a very reactive intermediate, and it can attack any nucleophile. In this case, the nucleophile is water. The water molecule can attack the mercurinium ion from either side, resulting in the formation of two different products: cis-2-methylcyclohexanol and trans-2-methylcyclohexanol.
The following is a diagram of the formation of cis-2-methylcyclohexanol:
The water molecule attacks the mercurinium ion from the top, resulting in the formation of cis-2-methylcyclohexanol.
The following is a diagram of the formation of trans-2-methylcyclohexanol:
The water molecule attacks the mercurinium ion from the bottom, resulting in the formation of trans-2-methylcyclohexanol.
Therefore, the oxymercuration-demercuration reaction of t-methylcyclohexene will produce a mixture of cis-2-methylcyclohexanol and trans-2-methylcyclohexanol.