1. For each set of structures, indicate which pairs of compounds are isomers (constitutional or geometric), which pairs are conformers, and which pairs are identical. For example, in part a, compare the relationships of A and B; A and C; B and C.
2. Write structural formulas for both chair conformations of each of the following compounds. (Line drawing is ok - but be very careful in your bond angles - axial versus equitorial must be obvious). Indicate which conformer is more stable and why.
a. cis-1-isopropyl-3-methylcyclohexane
b. trans- 1 -isopropyl-3-methylcyclohexane
c. cis-1-tent-butyl-4-ethylcyclohexane
d. cis-1 ,1 ,3 ,4-tetramethylcyclohexane
3. For the molecules below, estimate the energy difference between the most stable and next best conformation. Hint: the value of the axial strain energy of a hydroxy group is 900 calories; the value of the axial strain energy of a methyl group is 1700 calories.
Calculate the approximate ratio of the two at 300K.
4. Draw the most stable chair conformation of the sugar shown below:
