Use a Newman projection of the C3C4 bond of 2m4-dimethyl-3-phenyl-4-ethylhexane to show the most stable conformation first. Rotate through all of the eclipsed and staggered conformations. Using the energy values provided in the table below, calculate the relative energies of the different conformations. Plot the changes in energy in the graph diagram provided. Calculate a ratio of least stable to most stable based on H values. Hint: Draw a 2D structure first and “bold” the bond viewed in your Newman projection, then decide your line of sight. 2D structure Newman projections: lowest PE 2,4-dimethyl-3-phenyl-4-ethylhexane H) = Keq = 10 0 1 2 3 4 5 6 most stable least stable H) = 7 8 G H Keq = 10
H 2.3RT H Me Et i-Pr t-Bu Ph Br H 1.0 1.4 1.5 1.6 3.0 1.7 1.6 Me 1.4 2.5 2.7 3.0 8.5 3.3 2.8 Et 1.5 2.7 3.3 3.8 10.0 4.0 3.1 i-Pr 1.6 3.0 3.8 7.8 13.0 8.1 3.6 t-Bu 3.0 8.5 10.0 13.0 23.0 13.5 9.1 Ph 1.7 3.3 4.0 8.1 13.5 8.3 4.2 B