CHEMISTRY 222, Spring 2001
Review Problems
Page 1
There are 19 problems on 22 pages. Please make sure that you have them all.
1) Give an unambiguous name for the following compounds. Be
sure to use cis/trans, E/Z or R/S where appropriate.
OH
a)
cis-3-chlorocyclohexanol
Cl
Br
OH
4-bromo-2-propyl-1-hexanol
b)
OH
Br
2-bromo-5-nitrophenol
c)
NO2
O
1-penten-3-one
d)
e)
f)
1,(4E)-heptadien-6-yne
3-(1-methylpropyl)-1-heptyne
CHEMISTRY 222, Spring 2001
Review_Problems
Page 2
1) Contd.
CO2H
Br
g)
2-bromo-4-chlorobenzoic acid
Cl
H
N
N-propyl-4-methyl-3-octanamine
h)
CO2H
trans-1,3-cyclohexanedicarboxylic acid
i)
CO2H
CH3CH2
CH3
j)
CH3
E-2,5-dimethyl-5-octenoic acid
CH2 CH2 CH
H
CO2H
Br
k)
Br
l)
O
2-bromo-2-methylbutanoyl chloride
CH3 CH2 C
CH3
m)
2-bromopropanal
CHO
Cl
NC CH2 CH2 CH2 CH2 CO2 CH3
methyl-5-cyanopentanoate
CHEMISTRY 222, Spring 2001
Review Problems
Page 3
2) Rank the following in order of:
a)
Increasing acidity
OH
OH
H3C
NC
A
OH
OH
H3CO
B
C
–––
C
D
B
< A
––– < D
––– < –––
b) Increasing rate of reaction in a Diels-Alder reaction
A
C
B < –––
A
< –––
–––
c)
C
B
Increasing rate of reaction with an electrophile
NHCOCH3
NH2
A
B
A
–––
C
C
< –––
O–
OH
B
< –––
D
< –––
D
CHEMISTRY 222, Spring 2001
Review_Problems
Page 4
Question 2, contd.
g) Increasing acidity
O
O
O
O
O
O
OCH3
O
A
B
–––
f)
O
C
B
O
D
C < –––
A < –––
D
< –––
Increasing rate of hydrolysis
NHCOCH3
COCl
A
B
A–––
CO2CH3
C
< C
––– < B
–––
3) Give the number of enolizable hydrogens for each compound.
O
O
O
OH
4
–––
0
–––
H
1
–––
1
–––
CHEMISTRY 222, Spring 2001
4)
Review_Problems
Page 5
Rank the following in order of increasing energy
A
B
C
•
E
D
B
–––
5)
<
A
F
––– < –––
C
D
––– < –––
<
Draw the HOMO's (π orbitals) for the following systems:
•
–
6)
E
––– <
F
When in a flat configuration, which of the following compounds are:
•
a)
Aromatic?
A F
b)
Non-aromatic? B C D
–
N +
A
B
H
O
c)
Antiaromatic?
C
E
N
+
N+
H
D
E
F
CHEMISTRY 222, Spring 2001
Review Problems
Page 6
7) Give the alkyl bromides you would use to make the following
ketones using the dithiane synthesis shown.
R1-Br =
Br
1. BuLi
2. R1-X
3. BuLi
Ph
S
R2-Br =
S
Br
O
4. R2–X
5. H3O+
Ph
8) Propose a Wittig synthesis of 3-hexene, using 1-propene as your only
source of carbon
1. BH3.THF
2. –OH, H2O2
HBr
ROOR
OH
PCC
O
+
+
Ph3P –
C
H
1. PPh3
2. BuLi
Br
9) Give a synthesis of acetonitrile from ethanol
H3C CN
OH
POCl3
Na2Cr2O7/H2SO4
H3C CO2H
SOCl2
H3C COCl
NH3
H3C CONH2
CHEMISTRY 222, Spring 2001
Review Problems
Page 7
10) Keto-enol tautomerism can be catalyzed by base. The mechanism is shown below
for the case of acetone.
O–
O
CH2 C
H
HO–
CH2 C
CH3
O
–
CH2 C
CH3
A
O–
CH2 C
O
–
CH2 C
CH3
A
+ H2O
CH3
B
OH
+ H2O
CH3
CH2 C
CH3
B
a) The pKa of acetone is ca. 19, the pKa of water is ca. 16. Is deprotonation of
acetone by hydroxide exothermic or endothermic?
endothermic
b) Of A and B, which will be the major resonance contributor to the structure of
the enolate anion?
A
c) Draw a detailed (arrow pushing) mechanism for the acid catalyzed conversion of
acetone to its enol
H3O
OH2
+
+
OH H
H3C
C
OH H
CH2
H3C
C
+
CH2
O
H3C
C
OH
CH3
H3C
C
CH2
d) Draw a detailed (arrow pushing) mechanism for the reverse reaction.
OH2
+O
OH
H3O+
H3C
C
+
CH3
H3C
OH
H3C
C
O
CH2
H3C
C
CH3
C
H
CH3
CHEMISTRY 222, Spring 2001
Review Problems
Page 8
11) Here is an important acid catalyzed reaction which illustrates many of
the features of many acid catalyzed reactions. Give a complete arrow
pushing mechanism for the reaction.
O
H3O+
C
H3C
H
H3C
OH
O
H3O+
+ CH3CH2OH
H3C
+
H3C C O H
O+
C
C
OCH2CH3
OH2
+
+
HOH
CH3CH2 O
H3C C OH
OH
CH3CH2 O
OH
CH3CH2OH
OH
H3O+
H3C C OH
H3C C OH
CH3CH2
O+
H
OH2
CH3CH2 O
12) Give a complete arrow pushing mechanism for the following reaction. Be
careful indicate if any of the steps are reversible.
–
OCH3
O
O
Na+ –OCH3
H
CH3OH
heat
–
O HO
–
O
H2O
O
H OCH3
O
O HO
–
O
H
–
OCH3
CHEMISTRY 222, Spring 2001
Review Problems
Page 9
13) Give the major organic product for the following reactions. Show
stereochemistry where appropriate.
1. PBr3
2. Mg.THF
OH
a)
HO
3. CH3CHO
4. H3O+
O
O
Br2
Br
b)
H
Me
+
KMnO4, boil
HO2C
c)
t-Bu
t-Bu
O
O
heat
OH
d)
O
OH
O
O
O
H
O
e)
H
NaOEt
H
heat
OH
O
PCC
f)
H
OH
O
CHEMISTRY 222, Spring 2001
Review Problems
Page 10
13) Contd.
1. Sia2BH/THF
H
g)
CH2CHO
2. –OH, H2O2
NH2
O
+
1. H3O
H
h)
+ NH3
H
2. LiAlH4
1. SOCl2
i)
CO2H
2. AlCl3
O
heat/KMnO4
O
H3O+
j)
CO2H
O
NH
k)
2. H3O+ (neutralize)
Br
HO
NH2
D
1. Mg, THF
l)
O
1. –OH, H2O, heat
2. D2O
CHEMISTRY 222, Spring 2001
Review Problems
Page 11
13) Contd.
m)
O
O
EtO
OEt
2. H3O+/heat
NaCN
Br
o)
O
1. NaOEt/EtOH/heat
NC
CN
CN
CN
p)
heat
CN
heat
q)
O
O
O
r)
s)
+
O
NaOH, heat
OEt
N2+ –Cl
OH
H3O+
Br
Br2
t)
Br
CHEMISTRY 222, Spring 2001
Review Problems
Page 12
O
13) Contd.
1. CH3MgBr
CN
u)
2. H3O+
O
N
(CH3)2NH
v)
H3O+
O
N
(CH3)NH2
H3O+
w)
1. HBr, ROOR
x)
CN
2. NaCN
14) Give the reagents/conditions to perform the following transformations. Some will
require more than 1 reagent, in which case use the 1. ... and 2. ... notation.
OH
Cl
SOCl2
a)
O
Br
OH
b)
1. Br2/PBr3
O
OH
2. H2O
Na, NH3(l)
c)
d)
EtOH
CH3CH2 CH CH2
1. Hg(OAc) 2, EtOH
CH3CH2 CH CH3
OCH2CH3
2. NaBH4
1.
e)
CH3 C
C
O
MgBr
2. H3O
+
CH3 C
C
OH
CH3
CHEMISTRY 222, Spring 2001
Review Problems
Page 13
14) Contd.
f)
Ph C
C
1. Sia2BH.THF
H
Ph CH2 CHO
–
2. OH, H2O2
MCPBA
g)
O
O
OH
LiAlH4
h)
CH2OH
CO2CH3
O
Ph
1. PhMgBr
OH
2. H3O+
i)
H3C
Br2, hν
BrH2C
j)
t-Bu
t-Bu
CN
k)
1. LiAlH4
NH2
2. H3O+
O
HgSO4
l)
H2SO4
CN
H3CO
H3CO
m)
heat
CN
CHEMISTRY 222, Spring 2001
Review Problems
Page 14
15) Show how you would make compounds B from compounds A. Show
intermediates, reagents, but do not give arrow pushing mechanisms.
A
a)
H2N
NH2
1. KMnO4/–OH/heat
LiAlH4
+
2. H3O
CO2H
HO2C
CONH2
H2NOC
SOCl2
COCl
ClOC
OH
NH3
HO
b)
B
A
Na2Cr2O7
H2SO4
O
–
–
+
H3O+
O
HC C Na
OH
B
A
c)
Br2, hν
Br
K+ –Ot-Bu
1. PhMgBr
2. H3O+
K+ –Ot-Bu
OH
Na2Cr2O7
H2SO4
O
B
CHEMISTRY 222, Spring 2001
Review Problems
Page 15
15) Contd.
HO
CO2H
d)
A
B
H3O+
SOCl2
BrMgO
O
2 CH3MgBr
C
Cl
O
CO2H
e)
A
B
2 CH3Li
Li+
H3O+
–
O
+
O– Li
O
f)
CN
A
B
CN
PCC
heat
CN
HO
1. BH3.THF
2. –OH, H2O2
CN
CHEMISTRY 222, Spring 2001
15) Contd.
Review Problems
Page 16
Br
Br
g)
B
A
KOH
PBr3
OH
1. BH3.THF
2. –OH, H2O2
O
h)
CN
B
A
H3O+
AlCl3
OH
SOCl2
Cl
O
EtO
O
OEt
CO2H
i)
O
A
O
B
1. NaOH
H3O+, heat
2. CH3CH2Br
O
O
O
O
1. NaOH
EtO
OEt
EtO
2.
Br
OEt
CHEMISTRY 222, Spring 2001
Review Problems
Page 17
15) Contd.
F
j)
B
A
Br
HNO3/H2SO4
HBF4
N2+ Cl–
NO2
Br
NH2
NO2
Br2/FeBr3
NaNO2/HCl
H2, Pt
Br
Br
CO2H
k)
A
B
O
O
AlCl3
1. Mg.THF
2. CO2
3. H3O+
Cl
Br
Br2, hν
separate
isomers
O
O
CHEMISTRY 222, Spring 2001
Review Problems
Page 18
15) Contd.
you must make the ortho-isomer exclusively
with no contamination from the para-isomer
l)
Br
A
B
HNO3
H2SO4
H3PO2
H2
Pt
Br
Br2
separate
isomers here
HONO
FeBr3
NO2
Br
NH2
N2+
NH2
O
(hint, ethyl acetoacetic
ester synthesis)
Ph
m)
OH
Ph
A
B
PBr3
Ph
O
heat
Br
O
NaOEt
OEt
O
H3O+
O
OEt
O
O
OH
heat
Ph
Ph
CHEMISTRY 222, Spring 2001
Review Problems
Page 19
16) Determine the structure of the compound which has the IR, 13C and proton NMR spectra
given below. The molecular formula is C4H8O2. (This is an easy one!!)
sa16
O
O
3H
3H
2H
CHEMISTRY 222, Spring 2001
Review Problems
Page 20
Determine the structure of the
compound which has the IR,
13
C and proton NMR spectra
given below. The molecular
formula is C9H10O. (This is
easy too!!)
sa32
3H triplet
3H multiplet
2H multiplet
2H quartet
O
CHEMISTRY 222, Spring 2001
Review Problems
Page 21
sa50
18) Draw the structure
of the compound which
has the IR, 13C and
proton nmr spectra
given below. The
molecular formula is
C4H8O2. If you can not
determine the complete
structure, write as many
molecular fragments as
you can.
O
H3 C
CH2
O
CH3
3H
3H
This one is just a little bit harder!!
2H
CHEMISTRY 222, Spring 2--1
Review Problems
Page 22
sa53
19) Determine the structure of
the compound which has the
IR, 13C and proton NMR
spectra given below. The
molecular formula is C9H10O3.
HO2 C
O
X
this one is harder!
triplet
doublet
triplet
triplet
triplet