Name: CHM 332
FOURTH EXAMINATION
All answers should be written on the exam in the spaces provided. Clearly indicate your
answers in the spaces provided; if I have to guess as to what or where your answer is, it is wrong.
Where applicable, outline the logic or mystical principle you used to arrive at your answer, as partial
credit may be awarded for correct approaches.
You may assume that standard work-up conditions (i.e. those required to obtain a stable,
neutral product, like aqueous acid as example) follow each reaction on the exam. Clearly indicate
stereochemistry where appropriate. Be careful not to show stereochemistry where none exists.
This exam is long (as always) for the time allotted. You are strongly advised to read it through
completely before you begin.
(1)..10 pts...................._____
(2)..24 pts....................._____
(3)..21 pts....................._____
(4)..20 pts....................._____
(5)..16 pts....................._____
(6)..12 pts....................._____
TOTAL (103 pts)......…....._____
Percentage………………_____
2
1. [10 pts] Name the following molecules according to IUPAC rules:
a.
Cl
b. Name as an aniline compound:
H2N NO2
Cl
2. [24 pts] Fill in the necessary reagents for each of the following steps (A-H):
NO2 NH2
B
A C E
N2 +
1. Mg G F
2. CO2
CO2H H CN
A: ______________________________ B: ______________________________
C: ______________________________ D: ______________________________
E: ______________________________ F: ______________________________
G: ______________________________ H: ______________________________
3
3. [21 pts] Provide the appropriate reagents and conditions, or products for the following
transformations, in a single step.
a.
O2 N Br NaNH2
heat
NO2
b.
O H2, Pd/C
c.
CO2CH3
H3C
heat
d.
KMnO4, H2O
heat
e.
Br O
Cl
AlCl3
f.
HO3S Na, NH3
OCH3
g.
NO2
NH2
4
4. [20 pts] Propose a reasonable synthetic route to each of the following compounds, starting from
benzene. Partial credit will be given for approaches without reagents. Remember: Selectivity is the
name of the game-points will be deducted for reactions that result in ortho/para mixtures.
a.
Br
NH2
b.
Cl
H2 N OH
5
5. [16 pts] The following questions apply to the theoretical and historical aspects of benzene:
a. Explain how the monobromination experiment of benzene assisted in the assignment of the structure
of benzene, to which the molecular formula of C6H6 had been assigned. What key information did this
experiment provide?
Br2, Fe
C6H6 C6H5Br (only one product)
b. Explain how the second bromination experiment of bromobenzene assisted in the assignment of the
structure of benzene. What key information was gained from this experiment?
Br2, Fe
C6H5Br C6H4Br2 (three products)
c. Explain why 4n+2 is the perfect number of pi electrons for an aromatic system.
d. Explain why every atom in an aromatic system like benzene must be sp2 hybridized.
6
6. [12 pts] Short Answer: Answer 3 of the following 5 questions:
a. Circle the compound below that will have a higher wavelength (λmax) for ultraviolet absorption.
b. Propose a logical explanation as to why the first molecule shown below has a larger dipole moment
than the second molecule.
O
O
Ph Ph
Ph Ph
c. When HCl is added to 1,3-butadiene at room temperature or higher, the major product is 1-chloro-2-
butene. Explain why this forms in preference to 3-chloro-1-butene.
d. Predict which of the two following acids is more acidic. Provide an explanation for the differences
in acidity utilizing inductive and/or resonance effects in your answer (whatever is most applicable).
O O
O2N H3CO
OH OH
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e. Explain why an acyl group, like that found in acetophenone (shown below), is a meta director. Use
resonance forms in your discussion.
