CHEMISTRY 302
11:15 AM
EXAM 3
4 MAY 2012
Name: ________________________________________
Note: Your exam should consist of 5 pages including the cover page and grade tabulation sheet. Skim the
entire exam, and solve the easiest problems first. Exams not returned when time is called will not be
graded.
When drawing curved arrow mechanisms, if a structure is resonance stabilized, it is not necessary
to draw all resonance structures.
PLEASE DO NOT OPEN THIS EXAM UNTIL YOU ARE INSTRUCTED TO DO SO.
1
O
1. (14 pts) (a) Identify the most basic nitrogen in LSD. (b) Clearly explain why
that nitrogen is the most basic and why the other two nitrogens are less basic.
You must draw representative (not all!) resonance structures that are central
to your argument.
N
N
H
LSD
NH
2. (12 pts) Outline a synthesis of the following compound. The only aromatic
compound you are allowed to use as a reactant is benzene. You can assume
that any other nonaromatic reagents are available. Mechanisms are not
required.
H3C
OH
N
N
CH3
3. (12 pts) (a) Which of the following molecules will readily decarboxylate when heated? (b) Draw a
mechanism to illustrate the successful decarboxylation and formation of the product obtained from the
+
decarboxylation. Use H2O, H3O as needed.
O
O
OH
O
OH
O
2
4. (12 pts) 2-chloropyridine reacts with sodium methoxide via an addition-elimination mechanism. (a) Draw a
mechanism to show why 2-chloropyridine successfully reacts. (b) Explain why 3-chloropyridine does not
react. (b) Predict whether 4-chloropyridine will successfully react with sodium methoxide. Explain.
Cl
4
Cl
NaOMe
3
2
N
NaOMe
2
Cl
N
OMe
N
NaOMe
No
Reaction
?
N
5. (16 pts) Provide the major organic product from each of the following reactions. No mechanisms required.
H
N
(a)
1. cat HCl
2. NaBH3CN
O
(b)
Cl
1. NaCN
2. LAH
3. H3O+
O
NaOH
(c)
[Hint: α,β-unsaturated...]
∆
O
3
6. (34 pts) Write a full curved arrow mechanism for each of the following reactions:
O
O
a.
NaOH, H2O
O
O
O
b.
O
1. NaOEt
OEt
OEt
2. HCl
O
O
c.
1. LDA
2. CH3CH2Br
Predict the product structure in
addition to showing the
mechanism
4
CHEMISTRY 302
11:15 AM
EXAM 3
4 MAY 2012
Name: ________________________________________
Page
Points
2
38
3
28
4
34
Total
100
5
Score