1. (10) Choose one of the following phrases to
describe the relationship between the members of each pair below. Write the phrase on the line below the
structures. Structural isomers, configurational diastereomers, conformational
diastereomers, configurational enantiomers, conformational enantiomers.
a.
_____________________
b.
_____________________
2. (6) Select two of the structures below that could
be separated at room temperature
on the basis of a physical property like solubility. Write their identifying letters on the lines
below.
________
and ________
3. (5) If the heat of combustion of heptane is 1150
kcal/mol and if 3,3-dimethylpentane is 2 kcal/mol more stable than heptane,
what is the heat of combustion of 3,3-dimethylpentane?
_____________ kcal/mol
4. (10) What is the name of the compound below.
_________________________________
5. (10) Draw the most stable conformation of the
following compound. Full credit will not
be awarded unless your structure clearly shows the conformation according to
accepted conventions.
6. (8) Circle the chiral structures among the
following. (If there is a partially
erased or ambiguous circle, it will be marked wrong.)
7. (16) Draw the major organic substitution
product(s) of the following reactions.
Show the stereochemistry in your product structures.
a.
b.
8. (6) Draw the organic elimination product of the
following reaction.
9. (12) In each case draw the structures of the two
reactants that would lead to the nucleophilic substitution product
shown.
a.
Show the reactants needed to prepare:
b.
Show the reactants needed to prepare the following compound. Use only reagents that have no more than two
carbons.
10. (5) Suppose that only one halogen in the
following molecule is replaced by iodide under SN2 conditions (NaI
in acetone). Write the product of the
reaction.
11a. (10) Using the curved arrow formalism, draw an SN1
type of mechanism (with the same first step as the SN1 mechanism)
for the reaction below. Clearly show the
structure of the intermediate.
b. (2)
The compound shown above (compound A) reacts faster by an SN1
mechanism than its analogue below without a double bond (compound B) reacts by
an SN1 mechanism. Explain why
compound A reacts faster than compound B.
(Note that both are primary halides.)
CHE 230 – Organic Chemistry
Exam 2,
Name
________________________________ Student ID Number ________________
Before you begin this exam: First:
You are allowed to have a simple model set at your seat. Please put away all other materials. Second:
Place your student identification on your desk.
A proctor will come around to check everyone’s ID. Third:
Read through the entire exam. Do not
waste time on problems that you can’t do if there are others that look
easy. Fourth: It is critically important that your answers be written in
a clear, unambiguous manner. Answers in which your intentions are unclear will
not receive credit. Fifth: Read the instructions for each problem. You will have until
Problem Points Score
1 10 _____
2. 6 _____
3. 5 _____
4. 10 _____
5. 10 _____
6. 8 _____
7. 16 _____
8. 6 _____
9a. 6 _____
9b. 6 _____
10. 5 _____
11a. 10 _____
11b. 2 _____
Total 100 _______