235 – Organic II
IN-CLASS PROBLEM
In the space below, write an acceptable IUPAC
name for the following molecules:
Exam #2
9.
Chemistry 235,
Second Hour
Fall 2014 - Sample
Suggest
a synthes
Clearly show
is for each
necessary. reagents/reacta of the compo
unds
(4 points
nts
per box required next toshown on the right
the numbe
)
using the
rs on the
method shown
arrow; you
Exam
may add under the compo
additional
"numbers"und.
if
on the right.
(4 points each)for the compound shown
name
lature & M/C
the correct IUPAC
Section I – Nomenc
provided, give
1.
In the space
O
O
2.
O
a Claisen
OH
________________
1.
________________
__
________________
1.
O
O
2.
________
________________
2.
________________
O
__________
O
O
+
________________
________________
________________
H
an aldol
CH3
3.
O
3
Cl
1.
O
13
3
condensation
OOCH2 CH
__
C spectral data:
2.
129.7 ppm;
with the following
be most consistentsinglet, 127.5 ppm; doublet,
below would
129.1 ppm ;
compounds shown
50.0 ppm; doublet,
Which of the
e.
O
ppm; quartet,
167.0 ppm
d.
quartet, 22.0
O
ppm; singlet,
c.
O
O
CH 3O
singlet, 142.8
Cl
b.
OCH 3
a.
O
H CO
H
4.
OH
condensation
O
CH3
an acetoace
tic ester
synthesis
CH 3
C
5.
H3
O CH 3
OCH 3
will be:
1.
leaving group
best anionic
reaction, the
acyl transfer
2.
formed in an
l intermediate
In the tetrahedra
base
the strongest anion
a.
stable
b. the most with the highest pKa
the group
c.
group
conjugate acid
s?
d. the phenoxy
the weakest
compound
having
acyl
py of
the group
e.
of the
the spectrosco
parallels reactivity
is correct regarding
s in the IR generally 1.
of the following
6. Which
acyl compound
Br monoxide
of carbon
absorbance of
s is expulsion
of the carbonyl lic addition
2.
the frequency
of acyl compound
a.
towards nucleophicommon fragmentation
deshielded
acyl carbonyl
is very highly
the most
mass spectrum, e of carboxylic acid protons
b. in the
1
absorbanc
the H NMR
statements
c.
only, are correct
d. a and c, are correct statements
a, b and c
e.
O
an intramol
ecular aldol
condensation
O
O
alkylatio
n of an enamine
Cl
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© ChemistryOnline, 2009-2014
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IN-CLASS PROBLEM
IN-CLASS PROBLEM
4. Which of the compounds shown below would be
most consistent with the following 13C spectral data:
quartet, 22.0 ppm; quartet, 50.0 ppm; doublet, 129.1
ppm ; singlet, 127.5 ppm; doublet, 129.7 ppm; singlet,
142.8 ppm; singlet, 167.0 ppm
a.
O
b.
O
H3 C
O CH3
O
b.
O
c.
H
O CH3
OCH3
c.
H
O
d.
O
O
e.
d.
a. the strongest base
b. the most stable anion
c. the group with the highest pKa
d.O the phenoxy group
e.Clthe group having the weakest conjugate acid
e.
O
H3 CO
CH3 O
CH3
OCH3
H3 CO
5. In the tetrahedral intermediate formed in an acyl
transfer reaction, the best anionic leaving group
will be:
OCH3
O
CH3 O
CH3
OCH3
Cl
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IN-CLASS PROBLEM
IN-CLASS PROBLEM
6. Which of the following is correct regarding the
spectroscopy of acyl compounds?
a. the frequency of the carbonyl absorbance of
acyl compounds in the IR generally parallels
reactivity of the acyl carbonyl towards
nucleophilic addition
b. in the mass spectrum, the most common
fragmentation of acyl compounds is
expulsion of carbon monoxide
c. the 1H NMR absorbance of carboxylic acid
protons is very highly deshielded
d. a and c, only, are correct statements
e. a, b and c are correct statements
7.
Draw the major product for each of the following reactions; you should assume that "excess reagents" are present, if
appropriate. (2 points each)
O
O
NH2
+
H3 C
Cl
H C
N
3
O
H
++
Hg , Br 2 , CCl 4
Cl
OH
O
heat
O
O
+
H /heat
HO
H3 C
CH3
CH3
CH3
CH3
O
O
H3 C
Br
Cl
-
CH3 CH2 O
OCH2 CH3 +
mixed adduct only
O
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-78 ˚C
O
1. P, Br 2
OH
CH3
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O
(C6 H5 )2 CuLi
Cl
O
O
CH3
O
H
O
H
Br
2. H /H2 O
OH
(C6 H5 )2 CuLi
O
HO
O
CH3
CH3
+
O
+
O
O
CH3
O
H
++
Hg , Br 2 , CCl 4
Cl
OH
O
7.
7.
7.
heat
Br
Cl
O
O
+
H /heat
Draw the major product for each of the following reactions; you should assume that "excess reagents" are present, if
HO
appropriate. (2 points each)
CH3
H3 C
CH3
CH3
CH3
O
Draw the major product for each NH
of the
following reactions; you should assume that "excess reagents" are present, if O
2 +
O
O
O
appropriate.
(2 points
Draw
the major
producteach)
for each of the following reactions; you should assume that "excess reagents" are present, if
CH3 CH2 O
H3 C
Cl
H3 C
OCH2 CH3 +
appropriate. (2 points each)
O
OO
mixed adduct only
NH2
O
CH3
O
O
O
+
++
NH2
Hg , Br
,CCCl 4 N
+ H3 C
CH3
CH3
Cl
H23H
C
N
O
3
H3 C
Cl
O
Cl
OH
(C6 H5 )2 CuLi
heat
HH
O
++
Hg , Br 2 , CCl 4
O
H
Cl
-78
˚C
++
H
BrBr
Hg , Br 2 , CCl 4
Cl
OH O
ClCl
O
heat
+
IN-CClLASS PROBLEM
IN-CLASS PROBLEM
OH
heat
H /heat
O
Br O
1. P, Br 2
OO
HO
CH3
O
O
+
+
2.
H
/H
O
CH
OH
O
O
2
3
O
H /heat
H3HC C CHCH
OH
+
3
3
- 3
H /heat
O
HO
CH3 O
CH3 CH2 O
O
CHCH
H3HO
C
OCH2 CHCH
3+
3
3 CH
(C6 H5 )2 CuLi
3
3
O
mixed adductOonly
CH3
OO
CH3 O
O
O
O
CH3
CH3 CH3 CH2 OH3 C
OCH2 CH3 + O
CH3 CH2 O
O
mixed adduct only
OO
CHCH
H3 C
OCH2 CH3 + O
(C6 H5 )2 CuLi
3
O
3
O
mixed adduct only
CHCH
O H CH Cl
3
+
HO
-78 ˚C
3
3
O
+
OO
CH3
CH3
O
H
CH3
OH
(C6 H5 )2 CuLi
O
(C6 H5 )2 CuLi
O
H
Cl
O
O
-78 ˚C
1. P, Br H
2 H
H
Cl
-78 ˚C
(CH3 )2 NH
CH3
+
CH3
2. H /H2 O
OH
CH3
O
CH3
N
O
BrBr O
1. P, Br 2
O
O
CH
3
O
1. P,+Br 2
O
2. H /H2 O
(C6 H5 )2 CuLi
OH
+
OH
OHO
((CH3 )2 CH2 CH2 )2 AlH
OH
CH3 2. H /H2 O
O
H
O
no reaction at low temperature
(DIBAH)
(C6 H5 )2 CuLi
O
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2009-2014
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CHCH
3
3
(C
H
)
CuLi
6 5 2
O
CH3
O
O
CH3+
HO
CH3 CH2 O
+
CH3
H
CH3
OH
OO
CH2 CH3
CH3
O
O
CH3
O
O
O
+
HO
+
CH
O
3
CH
O
HO
(CH3 )2 NH
H
CH3
OH +
3
O
CH3
+
+
N
N
H
H /H2 O, heat
CH3
O
CH3
OH
OO
H
O
CH3
O
O
CH3
(CH3 )2 NH
CH3 O
CHCH
N N CH3
3
(CH3 )2 NH
CH3
O CH
3
3
((CH3 )2 CH2 CH2 )2 AlH CH
IN-CCH
LASS
POROBLEM
IN-CLASS PROBLEM
3
3
H
CH
3
O
8. For each of the conversions shown below, provide any required reagents and give the structures of missing
(DIBAH)
intermediates in the appropriate boxes. Clearly show stereochemistry, if appropriate. ( 2 points per box )
O
((CH3 )2 CH2 CH2 )2 AlH
H
O
no
reaction
at
low
temperature
((CH3 )2 CH2 CH2 )2 AlH no reaction
at low temperature
OCH2 CH3
H
CH3 (DIBAH) CH3 CH2 O
+
O
H /H2 O, heat
(DIBAH)
OCH2 CH3
CH3
O
Br
O
O
O
O
O
O
O
CH3 CH2 O
OH
OCH
CH
CH3
2
3
CH2 CH3
CH3 CH2 O
O
CH3
O CH
O O CH2 CH3
N 3
NCH3 CH2 OH+/H O, heatCHCH
3
OCH2 CH3
3
2
CH3
O
OO
+
N
N
H /H2 O, heat
H
+
N
N
H /H2 O, heat
CHCH
OO H
3
3
(CH CH ) CuLi
3
8.
2 2
O
O
For each of the conversions shown below, provide any required reagents and give the structures of missing
intermediates in the appropriate boxes. Clearly show stereochemistry, if appropriate. ( 2 points per box )
O
SOCl2
Cl
OH
OCH2 CH3
O
OCH2 CH3
+
H /H2 O, heat
Br
O
O
O
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Br
OH
OCH2 CH3
-
CH3 CH2 O
O
OCH2 CH3
O
O
O
H
1. Mg/ether
2. CO2
Br
3. H /H2 O
H
+
COOH
(CH3 CH2 )2 CuLi
O
O
SOCl2
O
Cl
OH
IN-CLASS PROBLEM
9.
((CH3 )3 O)3 AlLiH
I -C
P
Suggest aN
synthesis
for each ofROBLEM
the compounds shown on the right using the P(C
method
6 H 5 )3 shown under the compound.
LASS
1. the arrow; you may add additional "numbers" if
O
Clearly show reagents/reactants
required next to the numbers
on
O
necessary. (4 points per box )
H3 C
O
O
H
1. Mg/ether
2. CO2
Br
3. H /H2 O
+
+
2. H /H2 O
O
2
H
O
OCH2 CH3
-
1. CH3 CH2 O
+
2. H /H2 O, heat
COOH
a Claisen condensation
O
O
((CH3 )3 O)3 AlLiH
O
H3 C
P(C6 H5 )3
1.
O
Cl
H
O
Br
H3 C
H3 C
Cl
H
-
1. HO
2
H
H
+
2. H /H2 O
an aldol condensation
+
2. H /H2 O
O
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CH3
O
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OCH2 CH3
+
O
Br
-
CH3
1. CH3 CH2 O
+
2. H /H2 O, heat
an acetoacetic ester synthesis
O
O
-
O
1. HO
2. H+/H2 O
an intramolecular aldol condensation
9.
2. H /H2 O
Suggest a synthesis for each of the compounds shown on the right using the method shown under the compound.
Clearly show reagents/reactants required next to the numbers on the arrow; you may add additional "numbers" if
necessary. (4 points per box )
O
2
an aldol condensation
O
O
OCH2 CH3
-
1. CH3 CH2 O
CH3
O
OCH2 CH3
+
+
2. H /H2 O, heat
a Claisen condensation
O
-
Br
CH3
1. CH3 CH2 O
+
2. H /H2 O, heat
an acetoacetic ester synthesis
O
O
-
1. HO
H
H
+
2. H /H2 O
IN-CLASS PROBLEM
O
CH3
O
O
an aldol condensation
IN-CLASS PROBLEM
-
1. HO
O
2. H+/H2 O
O
an intramolecular aldol condensation
OCH2 CH3
+
O
Br
-
O
O
CH3
1. CH3 CH2 O
+
1.
N
2. H /H2 O, heat
Br
+
an acetoacetic ester synthesis
2. H /H2 O, heat
alkylation of an enamine
O
O
-
O
1. HO
2. H+/H2 O
an intramolecular aldol condensation
10. Compound A, on treatment with ethoxide in ethanol, followed by reaction with B gives compound C. Treament of
A with aqueous acid generates two moles of ethanol and an unstable compound which rapidly breaks down to yield
one mole of acetic acid and one mole of CO2 . Acid hydrolysis of compound C, followed by spontaneous
decarboxylation, gives D. Treatment of D with mercuric ion and Br 2 in CCl4 givs F. Compound F , on treatment
with tert-butoxide in tert-butanol (E2 conditions) forms (2-propenyl)benzene. The 1H NMR spectrum for compound
A and the IR spectrum of D are given on the following page. Interpret each of the spectra in the usual manner and
draw the structures of compounds A - E in the boxes below. (Structures are 20 points , total, and the spectra are
5 points each.)
© ChemistryOnline, 2009-2014
O
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O
C
A
N
1.
Br
O
CH3 CH2 O
O
-
1. CH 3 CH2 O /CH3 CH2 OH
O
+
2. H /H2 O, heat
O
OCH2 CH3
CH3 CH2 O
OCH2 CH3
2. B
alkylation of an enamine
Br
+
H /H2 O
IN-CLASS PROBLEM
IN-CLASS PROBLEM
10. Compound A, on treatment with ethoxide in
ethanol, followed by reaction with B gives
compound C. Treatment of A with aqueous acid
generates two moles of ethanol and an unstable
compound which rapidly breaks down to yield
one mole of acetic acid and one mole of CO2.
Acid hydrolysis of compound C, followed by
spontaneous decarboxylation, gives D.
Treatment of D with mercuric ion and Br2 in CCl4
givs F. Compound F , on treatment with tertbutoxide in tert-butanol (E2 conditions) forms
(2-ethenyl)benzene (styrene).
+
H /H2 O, heat
CH3 COOH + CO2 + 2 CH3 CH2 OH
D
E
O
Br
++
Hg , Br 2 , CCl 4
HO
heat
-
(CH3 )3 CO in (CH3 )3 COH
(E2)
© ChemistryOnline, 2009-2014
IN-CLASS PROBLEM
© ChemistryOnline, 2009-2014
IN-CLASS PROBLEM
3
6
2
24
7
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6
5
4
3
2
1
ppm, δ
0
© ChemistryOnline, 2009-2014
10. Compound A, on treatment with ethoxide in ethanol, followed by reaction with B gives compound C. Treament of
A with aqueous acid generates two moles of ethanol and an unstable compound which rapidly breaks down to yield
one mole of acetic acid and one mole of CO2 . Acid hydrolysis of compound C, followed by spontaneous
decarboxylation,
gives
D. treatment
Treatmentwith
of D
with mercuric
ion followed
and Br 2 in
F. Compound
F , on treatment
4 givswith
10. Compound
A, on
ethoxide
in ethanol,
byCCl
reaction
B gives compound
C. Treament of
A with aqueous
acid generates
two molesforms
of ethanol
and an unstable compound
whichspectrum
rapidly breaks
down to yield
with tert-butoxide
in tert-butanol
(E2 conditions)
(2-propenyl)benzene.
The 1H NMR
for compound
one
of acetic
one
of CO2 . page.
Acid hydrolysis
of compound
C, followed
by spontaneous
A and the
IRmole
spectrum
of Dacid
are and
given
onmole
the following
Interpret each
of the spectra
in the usual
manner and
draw thedecarboxylation,
structures of compounds
- E in theofboxes
below.
(Structures
points
, total, and the spectra are
gives D. A
Treatment
D with
mercuric
ion and are
Br 2 20
in CCl
4 givs F. Compound F , on treatment
5 points each.)
1
with tert-butoxide in tert-butanol (E2 conditions) forms (2-propenyl)benzene. The H NMR spectrum for compound
A and the IR spectrum of D are given on the following page. Interpret each of the spectra in the usual manner and
draw the structures of compounds A - E in the boxes below. (Structures are 20 points , total, and the spectra are
5 points each.)
IN-CLASS PROBLEM
C
A
O
CH3 CH2A
O
O
O
-
1. CH 3 CH2 O /CH3 CH2 OH
O
OCH2 CH3
O
O
O
-
1. CH 3 CH2 O /CH3 CH2 OH
OCH2 CH3
OCH2 CH3
C
2. B
O
CH3 CH2 O
CH3 CH2 O
CH3 CH2 O
OCH2 CH3
Br
2. B
Br
+
H /H2 O
+
H /H2 O, heat
+
H CH
/H2 OOH
CH3 COOH + CO2 + 2 CH
3
2
+
H /H2 O, heat
CH3 COOH + CO2 + 2 CH3 CH2 OH
D
E
O
Br
++
Hg , Br 2 , CCl 4
E
heat
Br
HO
D
O
++
Hg , Br 2 , CCl 4
HO
heat
© ChemistryOnline, 2009-2014
-
(CH3 )3 CO in (CH3 )3 COH
(E2)
-
(CH3 )3 CO in (CH3 )3 COH
(E2)
© ChemistryOnline, 2009-2014