Name: _________________________________
CHEM 332. Midterm 2
Sample Exam Problems
Prof Donald Watson
The following questions will be representative of the type that will appear on Midterm 2.
The actual exam contain approximately 4-6 such questions.
1
Name: _________________________________
2. (10 points)
(a) In acetone, what is the hybridization of the carbonyl C?
O
H3C
CH3
(b) Draw the major resonance structures of acetone.
(c) In a carbonyl fragment (C=O), which atom is electrophilic and which is nucleophilic?
(d) On the partial structures below, draw a 3-D picture of the C=O π and π* molecular
orbitals of acetone. Clearly indicate the geometry, phasing and relative sizes of the
lobes.
Me
Me
O
Me
O
Me
π
π*
2
Name: _________________________________
3. (20 points) Please provide the missing reagent(s) or expected major product in the
empty boxes below. If no reaction is expected, write “No Reaction.”
OH
Me
(a)
Me
Me
Me
O
Me
O
O
OH
(b)
O
MeO
OMe
(c)
F
NO2
NaOCH3
(d)
CH3OH, Δ
F
(e)
OH
Na2Cr2O7, H2SO4, H2O
3
Name: _________________________________
4. (8 points) Please draw a reasonable arrow-pushing mechanism for the following
reaction.
O
H
H
N
+
O 2N
NH2
NO2
catalytic H+
N
H
N
H
NO2
NO2
4
Name: _________________________________
5. (8 points) Provide a synthesis of 1-bromo-1-bromomethylcyclohexane from
cyclohexanone. You may use any other reagents you require.
Br
O
?
Br
5
Name: _________________________________
6. (8 points) Using 1-propanol as your only source of carbons, provide a synthesis of the
3-hexanone. You may use any inorganic reagents.
H3C
OH
?
O
H3C
CH3
6
Name: _________________________________
7. (10 Points) For each of the follow reactions, please predict the equilibrium position by
indicating if the reaction is strongly endothermic, strongly exothermic or approximately
thermoneutral. Write “endothermic”, “exothermic” or “neutral” in the boxes.
O
O
OH + Et3N
H2O
O Li
+
+
LiOH
O
OMe
OMe
O
Me +
N
H
Me
O
Me
Me
Me
H
N
Me
Me
Me
iPr
Me
+ Me
Me
+
N
Li
iPr
O
Me
OK
Et3NH
+
O
Li
Me +
N
Li
O
Me
Me
iPr
Me
Li
N
Me
Bu Li
Me
N
H
iPr
Me
+ Me
Me
+
OH
Bu H
Me
7
Name: _________________________________
8. (24 Points) Please provide the necessary reagents to complete the following transformations.
O
O
(a)
Me
Me
Me
Me
O
(b)
Me
Me
Me
OH
Me
OH
Bu
Bu
Me
OMe
Me
O
OH
(c)
O
Me
(d)
Me
Me
Me
Me
OH
O
Me
O
(e)
(f)
Me
Me
Me
Br
Me
Me
O
Me
NH2
8
Name: _________________________________
9. (18 Points) Please predict the product of the following reactions. If no reaction is expected,
state “No Reaction”.
Br
1) Mg
2) CO2
3) MeOH, HCl, heat
(a)
O
HCl, heat
OH
(b)
OH
1) LiAlH4 (excess)
2) H3O+
O
(c)
(d)
(e)
(f)
O
DCC, Me2NH
O
Me
OH
NaH; then MeI
O
Me
OH
LDA, –78 °C;
then MeI
O
Me
Et
Me
9
Name: _________________________________
10. (8 Points) Please provide a reasonable arrow-pushing mechanism for the following reaction.
O
Me
HCl, H2O
O
Me
O
Me
OH
10
Name: _________________________________
11. (7 points) Using 1-propanol as your only source of carbons, provide a synthesis of
propyl 2-methylpentanoate. You may use any inorganic reagents.
O
Me
OH
Me
Me
O
Me
11
Name: _________________________________
12. (7 Points) Please suggest a synthesis of amine 2 starting from acid 1 and any other
reagents you need that contain two (2) or less carbons.
Me
OH
Me
O
1
Me
Me
N
2
Me
Me
12