Download Exam 3 Review Sheet

Chemistry 213
Clark College
Exam 3 Review Sheet
The following questions have been pulled from various exams and review sheets from some of my
previous classes. The review is not complete! Make sure you study the assigned homeworks, go
through suggested problems and read through the Chapter Notes and your lecture notes.
Topic Outline
You should feel comfortable with the following topics:
Ch. 16 and 17: Aromatic Compounds
• Concepts of aromaticity: MO diagrams, Hückel Rules for Aromaticity, resonance structures
• Reactions at the benzylic position:
o Addition of Br or Cl with NBS/NCS in the presence of peroxide.
o Oxidation of a benzylic C-H with chromic acid or potassium permanganate.
• Nomenclature – common derivatives, o/m/p usage.
• Electrophilic Aromatic subsitution reactions.
o General mechanism, high energy intermediate.
o Generation of electrophile mechanisms.
o Halogenation: X2, FeX3.
o Sulfonation: H2SO4.
o Nitration: HNO3, H2SO4.
 Can be followed by H2/Ni reduction of nitro to an amine
o Friedel-Crafts alkylation: R-Cl, AlCl3.
 Watch for carbocation rearrangements!
o Friedel-Crafts acylation: acid chloride, AlCl3
 Can be followed by Wolff-Kishner (N2H4, KOH) or Clemmenson (Zn(Hg), HCl)
reduction to eliminate oxygen.
• Addition of the second and third groups
o ortho/para vs. meta directors.
 Resonance structures, inductive effects.
 Activating the ring.
• Synthesis of substituted benzenes, order of reaction for directing effects.
• Reactions of phenol:
o Kolbe carboxylation (plus mechanism)
Ch. 18 Aldehydes and Ketones
• Nomenclature of aldehydes and ketones, proper hierarchy in naming.
• Reactions of carbon nucleophiles with aldehydes and ketones, reactions and mechanisms.
o Grignard, lithium, alkyne, and cyanide nucleophiles to form alcohols.
o Wittig reagents to form alkenes.
• Nitrogen nucleophiles, reactions and mechanisms – acid catalysts, resonance structures and
equilibrium arrows.
o 1° amines to make imines
o 2° amines to make enamines
• Oxygen nucleophiles, reactions and mechanisms – use of acid catalysts
o Acetal formation
o Use of ethylene glycol (1,2-ethanediol) as a protecting group.
• Reductions of aldehydes and ketones.
o Understand the differences in the mechanisms/use of the various reducing agents –
polar vs. nonpolar reagents, hydride reagent mechanisms.
o Selectively reducing aldehydes/ketones, alkenes
• Oxidation of alcohols and aldehydes to either aldehydes, ketones or carboxylic acids.
o PCC/pyridine, chromic acid (H2CrO4), Tollens’ test (Ag(NH3)2+).
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
Review Problems
1. Which of the following compounds are aromatic?
O
H
As
OH
2. Predict the product(s). Predict the product(s) of the reactions below.
O
Zn(Hg), HCl, !
Cl2
FeCl3
NO2
1) KMnO4, !
2) H+
1) NaOH
2) CO2
3) H+
OH
H3CO
Cl
O2N
AlCl3
NH2
O
Cl
1) AlCl3
2) H2O
O
NBS, !
O-O
OH
1) NaOH
2) CO2
3) HCl
Br
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
3. Name the following molecules.
O
O
O
O
H
H3C
Cl
F
HO
4. More “predict the products”.
O
H+
OH
O
N
O
H
H+
H
1)
2) H3O+
O
O
EtNH2
H+
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
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
AlCl3
C14H20
1) BH3
2) OH-, H2O2,
H2O
AlCl3
SOCl2
pyridine
C14H20
H
Br
O
OH
OH
O
H
1) BrMg
2) H3O+
A
H2CrO4
OH
HO
B
H+
C
1) Hg(OAc)2,
H2O
2) NaBH4
D
SOCl2
pyr
G
C12H21N
Exam 1 Review
Spring 2008
H+
F
CH3NH2
DMSO
E
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Chemistry 213
Clark College
6. Provide the mechanisms for the following reactions.
O
H2SO4
HO
C5H10O3
H
cat.
N
O
NH2
H+
HO
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”.
b. Predict the major product.
c. Explain why the product you chose for part (b) should be the major product.
8. Synthesis. Make the following compounds from benzene.
NH2
Br
4 steps
Br
3 or 4
steps
9. Give the complete mechanism for the electrophilic bromination of benzene using Br2 and FeBr3.
Include the formation of the electrophile.
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
Cl
AlCl3
C10H14
NMR: d = 7.2 ppm, 2H, d
6.9 ppm, 2H, d
1.5 ppm, 1H, broad
1.3 pmm, 9H, s
11. Rank the following substituted benzene derivatives with respect to their reactivity toward the
electrophilic nitronium cation (1 = fastest, 5 = slowest).
Exam 1 Review
Spring 2008
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Chemistry 213
Clark College
OCH3
OCH3
O
NO2
O
Exam 1 Review
Spring 2008
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