Practice Exam-II
Name___________________________
(Last)
(First)
Student #________________________
This exam is divided up into two parts, multiple choice and short answer questions. All work
must be shown in order to receive full credit. Please turn off all electronic communication
devices.
Multiple choice questions: Choose the correct answer and record it on the scantron provided.
(2 points each)
1. What is the IUPAC name of the following compound?
a. (E)-3-methyl-5-vinyl-3-heptene
b. (Z)-1,3-diethyl-1-methyl-1,4-pentadiene
c. (Z)-3-ethyl-5-methyl-1,4-heptadiene
d. (E)-3-ethyl-5-methyl-1,4-heptadiene
2. Which of the following compounds does not have an index of hydrogen deficiency of 5?
O
N
NH2
a
b
c
d
3. Assign the compounds (in the order I to II) as Z or E
H3C
H3COOC
CN
C
HOH2C
(a) Z,Z
COOH
C
I
C
II
CH2NH(CH3)2
(b) Z,E
C
(c) E,Z
C(CH3)3
(d) E,E
4. Which of the following concepts explains Markovnikov’s rule as applied to the addition of
HBr to propene?
(a). the Aufbau principle
(b). the nucleophilicity of bromide anion
(c). the acidity of HBr
(d). the relative stability of carbocations
1
5. Which of the following has the highest value of
a
max
b
in the ultraviolet-visible spectrum?
c
d
6. What is the major organic product obtained from the following reaction?
1. Hg(OAc)2
H2 O
O
2. NaBH4
OH
OH
OH
a
b
c
d
7. What is the best choice of reagent(s) to perform the following transformation?
O
?
O
(a). OsO4; followed by NaHSO3
(c). BH3; followed by H2O2, NaOH
(b). Hg(OAc)2 and H2O; followed by NaBH4
(d). O3; followed by Zn/acetic acid.
8. Which of the following reactions of alkenes takes place with anti stereospecificity?
(a). dihydroxylation (treatment with OsO4 followed by NaHSO3)
(b). hydrogenation (treatment with H2/Pt)
(c). addition of HBr (treatment with HBr)
(d). bromination (treatment with Br2)
9. What is the major organic product obtained from the following reaction?
O
CH3
C
C
H
a
H2 O
b
O
HgSO4
H2SO4
OH
c
2
d
10. What is the major organic product obtained from the following reaction?
H3C
CH
C
C
CH3
H2
a
b
c
d
Lindlar Pd
H3C
11. What type of reactive intermediate is formed in the reaction of an alkene with Br2 and water
to give a bromohydrin?
(a) carbocation
(b) carbanion
(c) radical
(d) cyclic bromonium ion
12. Which of the following reactions of alkenes occur with anti stereospecificity?
(a) Hydroxylation
(c) hydrohalogenation
(b) hydrogenation
(d) bromohydrin formation
13. What is the correct order of stability of the following butenes?
1
(a) 1 > 2 > 3
2
3
(b) 1 > 3 > 2
(c) 3 > 2 > 1
(d) 2 > 3 > 1
14. Which of the following can exist as cis/trans isomers?
(a)
(b)
(c)
(d)
15. Which of the following concepts can be used to explain the order of carbocation stability
(3o>2o>1o)
(a) electronegativity
(b) resonance
(c) Inductive effect
(d) octet rule
3
Short answer questions
1.
Write the complete stepwise mechanism for the following reaction. Show all intermediate
structures and electron flow with arrows (10 points).
H3C
H3C
CH3
Br
CH3
HBr
Br2
2. What product would you expect from the reaction of cyclopentene with NBS and water?
What is the stereochemistry of the product formed. Explain the formation of this product by
drawing a detailed reaction mechanism (12 points).
4
3. Add curved arrows in the following reactions to show the flow of the electrons (12 points)
O
O
(a)
C
+
H
H3C
MgBr
MgBr
O
O
H
(c)
+
H
O
O
H
H3C
+
H
N
N
O
(b)
(d)
C
+
H
H3C
Cl
Cl
+
MgBr
CH4
+
HO
MgBr
H
(e)
OH
O
O
+
H
Cl
Cl
CH3
CH3
5
Cl
CH3
4. Give the structure of the principal organic product(s) in the following reactions indicating
both regiochemistry and stereochemistry when appropriate (16 points)?
HCl
(a)
H3C
CH3
(b)
CH2I2
Zn(Cu)
H
H
COOCH3
H2
Pd/C
(c)
COOCH3
CH3
Cl2
CCl4
(d)
CH3
Cl2
H2O
(e)
CH3
(f)
(g)
1. BH3
2. H2O2
1. OsO4
2. NaHSO3
2HBr
(h)
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5. Some of the following compounds can exhibit geometric (E/Z) isomerism, and some cannot.
Indicate which ones can and cannot show E/Z isomerism. Draw the structures of these
compounds including E and Z isomers (12 points):
(a) 3-bromo-2-chloro-2-pentene
(b) 3-bromo-2-methyl-2-butene
(c) 4-t-butyl-5-methyl-4-octene
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6. What combination of diene and dienophile undergoes Diels-Alder reaction to give each of
the following adducts (8 points)?
COOCH3
COOCH3
H
COOCH3
8