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Chem 14D Final Exam – P.1
Chem 14D–Final Exam Spring 2010 / Prof. Neil Garg
Thursday, June 10, 2010
11:30 AM–2:30 PM General Instructions: This is a standard
closed-note exam. Please read each question carefully and write
your answer neatly in the space provided using a black or blue pen
(no pencils!). Scrap paper and a periodic table are provided on the
final pages of the exam. You may detach these pages from the rest
of the exam. The use of model sets is allowed. Cell phones,
calculators, headphones are not permitted. Keep your Student ID
card out for ID Check. GOOD LUCK!
Problem Possible Points Score 1 20
2 20
3 20
4 10
5 30
Bonus 10
Total 100 +10 bonus
PLEASE PRINT & SIGN YOUR NAME BELOW TO ACKNOWLEDGE THAT YOU
WILL
ADHERE TO THE CHEM 14D HONOR CODE:
• On my honor, I will not give or receive any unauthorized aid
on this exam. _________________________________
_________________________________ Print Name / Student ID# Sign
Name
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Chem 14D Final Exam – P.2
1. Draw the major product for each of the following reactions.
Where applicable, answers without relative stereochemistry will be
given zero credit. (2 points each, 20 points total) a.
Me Et Me Et
H2, Pd/C
b.
MeMeheat
+
c.
H
O
n-butyllithium
OH
d.
O OMeMeO
H+
MeOH (excess)
e.
OMe
O
OEt
O
H+
EtOH
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Chem 14D Final Exam – P.3
1. Continued from previous page f.
Br
HNO3
H2SO4
Br
NO2
g.
OMe
O OH
MeMgBr
(2 equiv)
h.
OH
O
OH
LiAlH4
i.
NH2 NO2
F3CCO3H
j.
NO2
fuming
sulfuricacid
Me
OMe
NO2
Me
OMe
HO3S
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Chem 14D Final Exam – P.4
2. Provide the missing reagents for the transformations shown
below. (2 points each, 20 points total) a.
OH OPCC
b.
1. BH3
2. H2O2, NaOH
OH
c.
O O
BrBr2
AcOH d.
Br2
FeBr3
Br e.
Zn(Hg), HCl, heat
orH2NNH2, KOH, heat
orPd, H2, EtOH
O
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Chem 14D Final Exam – P.5
2. Continued from previous page f.
O
1. LDA
2. MeI
O
Me
g.
PCl3
or SOCl2OH
O
Cl
O
h.
HNMe2
heatOH
O
N
O
Me
Me
i.
OH CrO3
H+, H2O
OH
O
j.
O
HNaOH, H2O
Heat
O
H
O
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Chem 14D Final Exam – P.6
3. Provide a potential precursor to each of the following
compounds (in other words, perform a single-step retrosynthesis).
Also draw out the corresponding forward reaction with reagent that
could be used to synthesize the given molecule. (4 points each, 20
points total) Note: In many cases, there is more than one correct
solution a.
Identify precursor(s):
Forward reaction (provide starting material and reaction
conditions):
cat. H2SO4
benzene, heat
OH
OH
b.
Identify precursor(s):
Forward reaction (provide starting material and reaction
conditions):
MCPBAO
O
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Chem 14D Final Exam – P.7
3. Continued from previous page c.
Identify precursor(s):
Forward reaction (provide starting material and reaction
conditions):
Br2
FeBr3O2N Br
O2N
O2NO2N Br
d.
Identify precursor(s):
Forward reaction (provide starting material and reaction
conditions):
NMe
O
H+
H2NMe
NMe
O
e.
Identify precursor(s):
Forward reaction (provide starting material and reaction
conditions):
H
O
H
O
H
O+
H
ONaOH, H2O
heatH
O
H
O+
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Chem 14D Final Exam – P.8
4. Provide detailed arrow-pushing mechanisms for the following
transformations. (5 points each, 10 points total) a.
OEt
O
OH
O
EtOH
H+, Heat
OEt
O
OH
OH+
OH
OH
EtOH
OH
OH
OH
Et
EtOH
OH
OH
OEt
H+
O
OH
OEt
H
HOEt
O
H
EtOH
b.
OH O
AcOH
OH O
O
O
H OH
O
O
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Chem 14D Final Exam – P.9
5. Provide syntheses of the following target molecules. You may
use common reagents, fragments of 2-carbons or less (these
fragments may contain atoms other than just carbon, including
hydrogen, oxygen, MgBr, and Li), and any of the compounds shown in
the Chem 14D Toolbox. It is not necessary to show mechanisms or a
retrosynthetic analysis in your solution. (10 points each, 30
points totals)
Chem 14D Toolbox
H
O
Cl
O
OMe
Br
a.
OMe
O
OH
(naproxen, also known as "Aleve")
b.
OMe
O
c.
HN
O
Br
Place your final answers for questions 5A, 5B, and 5C on the
subsequent pages
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Chem 14D Final Exam – P.10
5a.
OMe
O
OH
(naproxen, also known as "Aleve")
OMe
Br
OMe
OH
OMe
Br
1. Mg
2.
H
O
PBr3 1. Mg
2. CO2
OMe
O
OH
[several possible solutions]
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Chem 14D Final Exam – P.11
5b.
OMe
O
OMe
O
1. n-butyllithium
2. CO2
CO2H
H+
MeOH
CO2Me
heat OMe
O
H2
Pd/C
[several possible solutions]
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Chem 14D Final Exam – P.12
5c.
HN
O
Br
HN
O
Br
HN
O
NH2NO2
HNO3
H2SO4
Zn(Hg)
HCl
Cl
O
Br2
FeBr3
[several possible solutions]
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Chem 14D Final Exam – P.13
Bonus #1: Fill in the blank (1 points): Fischer received the
Noble Prize in Chemistry in the year ____1902_____. Bonus #2: Draw
the product of the following reaction (you must show a structure).
(2 points extra credit) see lecture notes 3/29/10, Exam 1, Exam 2,
TA music video
NH
HN
O
O
NO2
H
O
NaOH
acetone
INDIGO!
Bonus #3: Consider the structure of sarain A. This beastly
molecule is typically drawn with a dotted line between N1 and C2,
as shown below. Explain what this dotted line represents. (3
points)
N N
HO
O
H
sarain A
2
1
OH
‘proximity interaction’ = the lone pair on N1 can attack the C2
carbonyl. Bonus #4: Provide a plausible synthetic scheme for the
conversion of compound A to compound B (4 points)
H
H
H
Me
Me
O
Me
Me
H
O
A B
?
H
Me
Me
O
A Bheat
Intramolecular
Diels-Alder !
