Chapter 3, Problem 3.40SP

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2—C3 bond. Place C2 in front, represented by three bonds coming together in a Y shape, and C3 in back, represented by a circle with three bonds pointing out from it. Define the dihedral angle as the angle between the methyl group on the front carbon and the ethyl group on the back carbon. Begin your graph at the 0° dihedral angle and begin to turn the front carbon. Show the Newman projection and the approximate energy at each 60° of rotation. Indicate which conformations are the most stable (lowest energy) and the least stable (highest energy).