Initials______________
Chemistry 634, Fall 2013
Midterm Exam
Prof. Donald Watson
340 points (75 mins)
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Closed note, closed book. No calculators allowed. You may use a molecular
model set.
Answers should be written in boxes provided. Other markings will not be
considered. Scratch paper can be found at the back of the exam packet.
Please initial each page at the top.
Points will only be awarded for clearly communicated answers.
Please make sure you have all pages of the exam packet (10 pages).
Name _______________________________________
Question 1: ________/100
Question 2: ________/60
Question 3: ________/50
Question 4: ________/50
Question 5: ________/80
_____________________
Total:_______/340
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Initials______________
1) (100 points) Please provide the reagents needed to carry out each of the following
transformations. Note, in each case, more than one step may be required.
OH
Me
O
O
Me
OH
Me
O
O
Me
OH
Me
NMe2
Me
O
O
Bn
N
NH
H
CN
O
_______/100 points
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Initials______________
2) (60 points, 6 points each) Complete the following equilibria, showing all products.
Using your knowledge of pka’s, predict the equilibrium constant for each reaction. In all
cases, please draw the expected product, even if the reaction is highly endothermic.
LDA
O
Me
OMe
Keq =
N
HCl
Keq =
NaOMe
O
Me
OMe
Keq =
Et3N
Ph
H
Keq =
tBuLi
CH3
Keq =
______/60 points
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Initials______________
3) (50 points) Provide a model that rationalizes the following selectivity.
H
O
H
LAH
H
OH
H
1
2 major
______/50 point
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Initials______________
4) (50 points) Please provide a detailed mechanism for the following reaction.
OH
(COCl)2
Et3N, DMSO
O
______/50 points
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Initials______________
5) (80 points) Starting with 3 as your only source of isotopically enriched starting
material, please propose a synthesis of isotopically labeled 4.
OMe
Me
OH
3
13C
=
4
______/80 points
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Initials______________
This page provided for scratch paper. No answers on this paper will be graded.
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Initials______________
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Initials______________
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Initials______________
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