Question

1. Draw an energy diagram showing the conformational analysis of the following compound, viewed along the C2-C3 bond. Clearly identify relative stability of staggered conformations as well as eclipsed conformations, taking into account gauche interactions and hydrogen-bonding interactions. Justify your choices through explicit reference to interactions occurring in various conformations.

C2

2. The IR spectrum of a dilute solution of compound 1 exhibits a signal at 3617 cm-1, while the IR spectrum of a dilute solution of compound 2 exhibits a signal at 3594 cm-1.

a) Draw both compounds in their lowest energy chair conformations.

b) Explain why the signal for compound 2 appears at a lower wavenumber of absorption.

c) Identify the signal that you expect to be broader, explaining the chemical basis for your

choice.

d) Draw one enantiomer and two diastereomers of compound 2, clearly identifying each.

e) Identify each of the four chiral centers on the leftmost ring of compound 2 as being in

the R or S configuration.

Answer 1