First_____________________
Name: Last_________________________
CWID:___________________
Seat Number:____________________
Chemistry 3053
Exam 4, 100 points
Thursday, November 17, 2011
GENERAL INSTRUCTIONS:
1)
2)
3)
4)
Write name, CWID, and seat number on this page
Check for 11 pages (including this one and the last page with the periodic table).
Sign the attendance sheet when you turn in your exam.
Keep your exam flat on the desk in front of you.
You may only have a writing utensil.
EVERYTHING ELSE MUST BE PUT AWAY.
No cell phones
No calculators
No electronic devices of any kind.
Show Your Work. Be Specific With Your Answers and Write Legibly
(if we cant read it, we cant grade it)
GOOD LUCK
When your exam is returned, your score will be on the last page.
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1) For the following alkene and indicated reagents give the expected product(s) in the boxes
provided. Show the stereoisomers that are formed where applicable.
(12 points)
???
Product(s)
Br2
a)
H2O
1) BH3
b)
2) H2O2, -OH
1) O3
c)
2) Me2S
HBr
d)
2) Mark the letter answer legibly (A, B, C, or D) for each question in the blank to the left.
(14 points)
________ a) For a hydroboration/oxidation reaction on the starting alkene, identify the major
product.
CH3
A)
HO
B)
C)
CH3
OH
2
H3C OH
D)
H3C Br
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________ b) For the following acid catalyzed hydration reaction, identify the major product.
H+
A)
B)
OH
C)
HO
D)
HO
H2O
Br
________ c) Identify which conditions would afford the alkyne from the alkene.
1) ???
2) ???
C)
B)
A)
1) Cl2
1) H3
2) NaOH (excess)
2) H-Br
D)
1) H-Br
1) Br2
2) NaOH (excess)
O+
2) NaNH2 (excess)
________ d) Identify the conditions that would afford the product from the given alkene.
Br
???
Br
A)
C)
B)
Cl2
H-Br
D)
1) BH3
2) H2O2/ -OH
Br2
________ e) For the following acid catalyzed dehydration reaction, identify the MAJOR product.
H2SO4
OH
heat
C)
B)
A)
D)
________ f) For the following 2 carbocation, identify the most stable rearrangement product.
CH3
A)
CH3
CH3
C)
B)
CH3
CH3
D)
CH2
________ g) Identify which set of bases is in the appropriate order based upon base strength.
B)
A)
-OH
> -CH2CH3
>
-NH
2
>
-OH
CHCH2
C)
<
-NH
2
<
CH CH2 <
H2O
<
CH2CH3
D)
-OH
>
-NH
2
>
CH >
-OH
H2O
3 CH2
<
C CH
-NH2 <
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3) For the following alkyne and indicated reagents give the expected product(s) in the boxes
provided.
(12 points)
???
a)
b)
Product(s)
2.0 equivalents
Br2
Li, Et2NH
NH3
c)
1) O3
2) AcOH
d)
2.0 equivalents
HCl
4
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4) Show how the given product could be synthesized from the given starting material. More than
one synthetic step is required. (Fill in the boxes)
(18 points)
A)
OH
OH
CH3
CH3
Br
B)
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C)
5) Propose a plausible mechanism that accounts for the formation of the product from the given
starting material under the conditions provided.
(5 points)
H3O+
6
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6) Give the structures of the possible starting materials that would afford the given products
under the reaction conditions provided.
(12 points)
A)
O
1) KMnO4, -OH
HO
2) H3O+
OH
O
B)
Br
Br
Br2
C)
H2SO4
D)
1) BH3
OH
2) H2O2, -OH
7
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7) Give the major product that would be formed when each of the following alcohols are
subjected to acid-catalyzed dehydration.
(6 points)
A)
OH
B)
OH
8) Given the following information, give the structures for unknown compounds A, B, and C.
(9 points)
t-BuO-
B = C9H14Cl2
A = C8H14
CHCl3
HBr
1) KMnO4, -OH, heat
2)H3O+
OH
O
O
OH
C = C8H15Br
A=
B=
C=
8
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9) Explain BRIEFLY, why Hydroboration/Oxidation affords the anti-Markovnikov product
(mechanisms and structures are your friends)
(5 points)
1 0)
a) Using 1,4-dimethylcyclohexene, demonstrate that addition of HBr is not a stereospecific
reaction. Draw the structures of all the stereoisomers formed from addition of HBr to the alkene.
(4 points)
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b) Using 1,4-dimethylcyclohexene, demonstrate that addition of HBr is a regioselective reaction.
(3 points)
Extra Credit: (6 points)
Why is compound X formed in the following reaction, instead of its constitutional isomer Y?
(Use mechanism and structural reasoning)
Cl
HCl
NOT
O
O
X
Cl
O
Y
10
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Scratch Paper Only Nothing written on this page will be graded.
Score: _________________________
11
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