Identify a True Statement About Trans-2-Methylcyclohexanol

Question

Identify a true statement about trans-2-methylcyclohexanol.
A) The hydroxyl group and the methyl group lie in the plane that contains the cyclohexane ring.
B) The methyl group may lie above and the hydroxyl group may lie below the plane that contains the cyclohexane ring.
C) The methyl group and the hydroxyl group lie above the plane that contains the cyclohexane ring.
D) The methyl group and the hydroxyl group lie below the plane that contains the cyclohexane ring.

Accepted Answer

In trans-2-methylcyclohexanol, the hydroxyl group and the methyl group are located on opposite sides of the cyclohexane ring, making it trans. The cyclohexane ring is not planar, but rather adopts a chair conformation where the carbon atoms alternate between sp3 hybridization and p orbitals. The axial positions are perpendicular to the plane of the equatorial positions. The hydroxyl group and the methyl group are both in equatorial positions, but they can be oriented above or below the plane of the ring. Since the hydroxyl group has a higher priority than the methyl group in assigning stereochemistry, it is assigned to be "down" and the methyl group is "up" in the IUPAC nomenclature. Therefore, option B is correct.