In a conformational energy diagram for cyclohexane, which of the following conformations corresponds to the highest potential energy due to steric strain?

The highest‑energy conformation of cyclohexane is the boat form, because it forces many atoms to be close together, creating severe steric clashes and torsional strain. In the boat shape, several hydrogens on adjacent carbons are forced into gauche positions, causing both eclipsing interactions and 1,3‑dipole repulsions. These repulsions raise the potential energy above that of the chair, which is the most stable conformation. For example, in a boat, two axial hydrogens on the same side of the ring are only about 2. 5 Å apart, far closer than the 3.