Exam 2
Chemistry 122
April 19, 2007
Do not open or begin this exam until instructed. This exam consists of 6 pages plus the cover
page. Before starting the exam, check to make sure that you have all of the pages. The exam has
a total of 100 points and includes 11 questions. Only legible answers written on the exam will be
considered for grading. All pertinent information needed for the exam is given. Notes and
textbooks are not permitted. Use your time wisely.
This exam is administered under the Wake Forest Honor Code.
Name_______________________________________
1. (6 points, 2 each) Provide IUPAC accepted names for the following compounds.
Br
2. (4 points, 2 each) Classify each of the following dienes as conjugated, cumulated, or
isolated.
3. (2 points) Which of the following carbocations would be most likely to undergo a
rearrangement?
4. (2 points) What is the oxidation state (or level) of the indicated carbon?
O
OH
5. (6 points) Draw a generic reaction energy diagram that fits the following profile: 1) the
reaction is endothermic, 2) the reaction occurs in two steps mechanistically, and 3) the
first step of the mechanism is rate determining. Be sure to label both axes.
1
6. (10 points, 2 each) Circle the reaction in each pair that would be faster.
Br
+
NaCN
+
NaCN
Br
25 oC
CN
DMSO
+
NaBr
+
NaBr
25 oC
DMSO
CN
_________________________________________________________
Cl
Cl
+
+
NaCN
NaCN
25 oC
DMSO
CN
+
NaBr
CN
+
NaBr
25 oC
ethanol
_________________________________________________________
I
OCH3
(+ CH3OH2 + I )
CH3OH
I
OCH3
(+ CH3OH2 + I )
CH3OH
_________________________________________________________
Cl
I
+
NaI
+
NaI
DMSO
Br
+
NaCl
+
NaBr
I
DMSO
_________________________________________________________
Br
+ (CH3)3COK
80 oC
+ (CH3)3COH + KBr
(CH3)3COH
Br + (CH3)3COK
25 oC
+ (CH3)3COH + KBr
(CH3)3COH
_________________________________________________________
2
7. a. (6 points) Draw the four -molecular orbitals of 1,3-butadiene. Show electrons in the
orbitals that are filled. Label the HOMO and the LUMO.
b. (3 points) Do the same for the two -molecular orbitals of ethene.
c. (1 point) Would a reaction involving the HOMO of butadiene and the LUMO of ethene
be symmetry allowed?
energy
ethene
energy
1,3-butadiene
8. (36 points, 3 each) Provide structures for the major organic products of each of the
following reactions. If more than one compound is expected, indicate which will be
formed in greatest yield. Be careful to indicate product geometry when necessary.
1) BH3
2) H2O2, NaOH, H2O
OTs
+
NaSCH2CH3
DMSO
3
O
+

O
+
OH
HCl
1) OsO4
2) NaHSO3, H2O
+
HBr
(1 equivalent)
Li
NH3
Br
Br
+
CH3OH
O
Cl S
O
+
OH
H
NaOCH3
(excess)
pyridine
25 oC
Cl
CH3CH2OH
1) O3
2) Zn, H2O
Br
+
NaOCH3
CH3OH
4
9. (8 points) Provide a complete electron-pushing mechanism for the following reaction.
Include by-products as they are formed.
Cl
Cl2
CH3CH2OH
H
H
OCH2CH3
10. (8 points) Provide a synthesis of 2-bromopentane. You may begin with any organic
reagents containing three carbons or less and any inorganic reagents you need.
5
Choose one of the following problems. Clearly indicate which one you are omitting.
11. (8 points) Provide a complete electron-pushing mechanism for the following reaction.
HBr
Br
H2O2

OR
Provide a synthesis of the following target compound. You may beginning with any organic
reagents containing four carbons or less and any inorganic reagents you need.
O
O
H
6