Chemistry 213
Clark College
Exam 3 Review Sheet SOLUTION
Review Problems
1. Which of the following compounds are aromatic?
O
H
As
OH
No! Does not have
4n+2 pi electrons.
No! The alcohol C
is sp3-hybridized.
2. Predict the product(s). Predict the product(s) of the reactions below.
O
Zn(Hg), HCl, !
Cl
Cl2
FeCl3
NO2
NO2
O
1) KMnO4, !
2) H+
OH
OH
1) NaOH
2) CO2
3) H+
OH
O
OH
H3CO
H3CO
Cl
O2N
O2N
AlCl3
NH2
O
O
NH2
NH2
Cl
1) AlCl3
2) H2O
O
Exam 1 Review
O
Spring 2008
O
O
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Chemistry 213
Clark College
NBS, !
O-O
Br
1) NaOH
2) CO2
3) HCl
OH
OH
Br
OH
Br
O
3. Name the following molecules.
O
O
O
H
H3C
Cl
4-methyl-3-oxopentanal
(3R,4S)-3-chloro-4methylcyclopentanone
O
F
HO
m-fluoroacetophenone
(3R,5S)-4-isopropyl-2-methyl-5-phenylheptan-3-ol
4. More “predict the products”.
O
5
4
3
2
OH
O
HO
H+
1
O
Ph3P
N
O
H
Exam 1 Review
N
H
H+
H
Spring 2008
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Chemistry 213
Clark College
1)
2) H3O+
O
OH
O
N
EtNH2
H+
5. “Road Map”. Fill in the products or provide the reagents of each step of the synthetic sequences.
Some molecular formulas are given to help you stay on track.
OH
SOCl2
pyridine
Cl
AlCl3
C14H20
1) BH3
2) OH-, H2O2,
H2O
Cl
OH
AlCl3
SOCl2
pyridine
C14H20
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
LDA
1) BH3
2) H2O2, NaOH
H2O
Br
PCC
Pyridine
H
O
OH
1) PhMgBr
2) H+
OH
O
1) BrMg
2) H3O+
H
OH
O
H2CrO4
H+
A
O
CH3NH2
DMSO
OH
HO
O
Cl
B
O
SOCl2
pyr
O
OH
E
1) Hg(OAc)2,
H2O
2) NaBH4
O
O
D
C
O
O
NH
H+
O
N
NH
G
C12H21N
F
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
6. Provide the mechanisms for the following reactions.
O
H2SO4
HO
C5H10O3
H
cat.
HO
O
HO
H
O
H2SO4
cat.
HO
HO
Using this alcohol
makes a more stable
ring size for the
formed cyclic acetal!
H
O
HO
H
H
H
HO
HO
O
C5H10O3
H
O
OH
OH
OH
OH
N
O
NH2
H+
O
NH2
H
N
N
Exam 1 Review
H
H
O
N
H+
H
N
Spring 2008
H
OH
H
N
N
H
OH
N
H
H+
OH2
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Chemistry 213
Clark College
7. Methoxypyridine can form two different monochlorinated products.
OCH3
Cl2
FeCl3
Two isomeric products, C6H6ClNO
N
a. Give the structures of both products and label them “A” and “B”.
OCH3
OCH3
Cl
N
N
Cl
A
B
b. Predict the major product.
A
c. Explain why the product you chose for part (b) should be the major product.
The lone pairs on the methoxy group can add an additional resonance structure to the carbocation
intermediate formed for molecule A. This is not the case for compound B, as the lone pair on Nitrogen
is in an sp2-hybridized orbital that is outside of the pi cloud, and cannot be used for resonance
structures.
8. Synthesis. Make the following compounds from benzene.
NH2
4 steps
O
1) Cl
AlCl3
2) H2O
O
Br
N2H4, !, OH-
NBS, !
O-O
1) NH3
2) OHNH2
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
Br
Br
O
Br2
FeBr3
O
Cl
AlCl3
Br
N2H4,
OH-, !
Br
Br
NBS
h!
Br
Br
3 or 4
steps
PPh3
H
1) BH3
2) H2O2, NaOH
H2O
PCC
Pyridine
OH
HBr
ROOR
Br
H
O
1) PPH3
2) nBuLi
3)
O
9. Give the complete mechanism for the electrophilic bromination of benzene using Br2 and FeBr3.
Include the formation of the electrophile.
Br
Br Br
FeBr3
Br3Fe Br Br
H
Br3Fe Br
H
Br
H
Br
H
Br
H
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
10. NMR. Phenol undergoes a Friedel-Crafts reaction with t-butyl chloride in the presence of aluminum
chloride. Only one product is formed, and NMR data for the product is shown below. With this
information, give the identity of this product.
OH
The "doublet
of doublets"
indicates para
subsitution.
OH
Cl
NMR: d = 7.2 ppm, 2H, d
6.9 ppm, 2H, d
1.5 ppm, 1H, broad
1.3 pmm, 9H, s
AlCl3
11. Rank the following substituted benzene derivatives with respect to their reactivity toward the
electrophilic nitronium cation (1 = fastest, 5 = slowest).
OCH3
OCH3
2
1
O
NO2
O
Exam 1 Review
4
Spring 2008
5
3
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