Chemistry 14D
Winter 2017
Final Exam Part A
Page 1
Please use the backs of the exam pages for scratch space. Please do not use the exam
margins for this purpose.
All reactants and solvents written above and below the reaction arrows are assumed to
present in excess, unless otherwise specified (i.e., cat.).
OK use 'Ph' anywhere on this exam where appropriate.
1.
(2) Complete this statement by adding no more than fifteen words: A carbonyl group is electrophilic because...
2.
(3) Complete this reaction by writing the
missing reactant(s) and solvent(s) in the
box:
O
(6) Write a mechanism:
CH2OH
OH
H
HO
HO
HO
4.
HO
H3C
OCH3
H3C
3.
O
H2O
H3C
CH3
OCH3
H3C
CH3
CH2OH
O
OH
HO
HO
HO
O
(2) In lecture we learned of the three common carbonyl fates. In the space below write the name(s) of all of these
fates that do not occur in the mechanism of question 3. If all of the common carbonyl fates are used write, "all are
used".
O
H2O
Questions 5–10 refer to this reaction:
Cl
5.
O
Cl
(3) Write the major organic product of this reaction in the box above. Give extra thought to this answer, because a
wrong answer for this question may cause you to write wrong answers for questions some below.
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Chemistry 14D
6.
Winter 2017
Final Exam Part A
Page 2
(4) Complete each statement by adding no more than ten words in each case. The two reasons must be very
different.
(a) This hydrolysis reaction of question 5 cannot involve an enolate because...
(b) This hydrolysis reaction of question 5 cannot involve an enolate because...
7.
(3) In the box below write another molecule that undergoes
hydrolysis at least as quickly as phosgene, and gives the same
product as you wrote in question 5.
H2O
Same product
as question 5.
8.
(3) In the box below write another molecule that undergoes
hydrolysis obviously more slowly than phosgene, and gives the
same product as you wrote in question 5.
H2O
Same product
as question 5.
9.
(4) Complete each statement by adding no more than ten words in each case. The two reasons must be very
different.
(a) The hydrolysis reaction of question 8 is slower than the hydrolysis of phosgene in question 5 because...
(b) The hydrolysis reaction of question 8 is slower than the hydrolysis of phosgene in question 5 because...
10. (8) For each reaction below, write the major product in the product box, then in the rate box write 'F' for faster if this
reaction is faster than the reaction of phosgene with water alone (i.e., no H2SO4 or NaOH), 'S' if the reaction is
slower, or 'N' if it occurs at nearly the same rate.
Major product
O
H2SO 4
(a)
Cl
Rate
Cl
H2O
O
NaOH
(b)
Cl
Cl
H2O
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Chemistry 14D
Winter 2017
Final Exam Part A
Page 3
O
O
cat. H2SO 4
11. (10) Write a complete mechanism for this reaction:
OH
CH3OH
OCH3
O
1. CH3MgBr
12. (3) In the box write the major product of the
following reaction:
OCH3
2. H3O+
13. (8) Write a mechanism for the formation of the major organic product of the reaction in question 12.
14. (3) The Weinreb amide shown below reacts with CH3MgBr to form a ketone as the final reaction product. With this
thought in mind, predict the major product (i.e., write it in the product box) of the reaction of the Weinreb amide with
the alkyne anion shown below. If no reaction is likely, write "NR" for no reaction in the product box.
O
N
OCH3
1.
C
CCH3
2. H3O+
CH3
Weinreb amide
Product
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Chemistry 14D
Winter 2017
Final Exam Part A
Page 4
15. (3) Complete this reaction for a likely synthesis of the Weinreb amide of question 14 by writing one structure in each
empty box.
H3C
OCH3
N
H
O
H
OCH3
N
CH3
16. (10) Imines are ubiquitous in biology, appearing in a wide range of chemical processes including vision, diabetes, and
glucose metabolism. As an example of imine formation, write a mechanism for the following enzyme-catalyzed
imine-forming reaction. For this reaction, Enz-H is a weak acid and Enz: is a weak base.
O
H3C
N
CH3 NH2
CH3
CH3
Enz-H, Enz:
H3C
CH3
O
17. (6) Consider the rate of the reaction in question 16 if acetone is changed to benzaldehyde.
Complete each statement below by adding no more than fifteen words in each case. Be specific
and precise.
H
Benzaldehyde
(a) One factor that might make the imine formation reaction with benzaldehyde faster than the imine formation
reaction with acetone is...
(a) One factor that might make the imine formation reaction with benzaldehyde slower than the imine formation
reaction with acetone is...
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Chemistry 14D
Winter 2017
Final Exam Part A
O
18. (3) Write the major product in the box:
Page 5
(CH3)2 NH
cat. H2SO 4
CH3
19. (2) In the box below each structure write the pKa of the
indicated hydrogen atom. pKa choices: 23, 17, and 7. Each
number will be used exactly once.
20. (3) The product of this reaction has molecular formula
C16H14O. Draw the structure of this product in the
box.
H3C
Ph
OCH3
H3C
OPh
Ph
O
Ph
NaOH
CH3
NaOCH3
21. (8) Write the mechanism for this reaction:
O
O
Ph
O
O
H3C
O
CH3OH
CH3OH
O
O
OCH3
22. (3) In the blank after concept, write the number of one exam question, such as 68(q), in which that concept occurs. If
the concept occurs more than once write just one exam question number. If the concept does not occur anywhere on
this exam write "99" in the blank.
Organometallic reagent: _______ Fischer esterification: _______ Strong acid catalysis: ________
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