Chemistry 216
Second Examination
April 19th, 2005
Name____________________
Please print
Professor John Nanos
135 points)
(2.0 hr, 120
Signature _______________________
Student ID # _____________________
Please CHECK OFF your lab section.
(minus 3 points for no check)
Monday _____110
_____111
_____112
_____113
_____310
_____311
_____312
Todd Senecal
Tuesday _____130
Eric Wiedner
_____131
Josephine Nakhla
_____132
Jonathon Fritz
_____133
Marisa MacNaughtan
_____134
Mike Purkey
_____330
Joseph Hunt
_____331
_____332
_____333
_____334
Wednes- _____150
day
_____151
_____152
_____153
_____154
_____351
_____352
_____353
_____354
Gayle Gawlik
Tara Conser
Eric Wiedner
Todd Groendyke
William Lai
Marisa Mac.
Brian Brennan
Greg Less
Josephine Nakhla
Thursday _____170
_____171
_____172
_____370
_____371
_____376
_____372
_____373
_____374
_____375
Lothar Steffens
Christine Nguyen
Geoff Halvorsen
Jun Pan
Jinhui Chen
Tony Wildon
Greg Less
Todd Groendyke
Tara Conser
Jonathon Fritz
Lothar Steffens
Christine Nguyen
Geoff Halvorsen
Brian Brennan
William Lai
Jun Pan
Joseph Hunt
Tony Wildon
Gayle Gawlik
Jinhui Chen
2
11
3
24
4
10
5
16
6
06
7
06
8
06
9
09
10
12
11
21
12
08
13
06
TOTAL
135
Page 2. Chem. 216 Winter 2005
Name:________________________
I. Reaction products A, B, C, and D are all examples of the Diels-Alder reaction and they all
proceed with different reaction rates. In the box provided, arrange the reactions (A-D) in order
of reaction rates from fastest to slowest.
NO2
A
+
B
+
OCH3
NO2
<
<
D
+
C
+
<
Fastest reaction
4pts
Slowest reaction
II. In the box provided, respond with the appropriate letter chosen from the list below. 1pt each.
1.
2.
3.
4.
5.
6.
7.
What type of reaction apparatus do we use if we want to drive the reaction to
completion faster than at room temperature?
Name a technique used to purify a liquid product.
What is the name of the reaction which utilizes magnesium and organobromide as
critical reaction elements?
Assuming that all the products and reactants were visualized, how many spots would
we observed at 50% completion of a Wittig reaction?
Column chromatography is the bulk scale version of what technique that we utilized
on many occasions during the semester?
Which is the more abundant and sensitive nuclei commonly analyzed with the NMR
technique?
As magnetic strengths decreases, sensitivity and signal-to-noise _____________?
(a) Reflux
(b) Column chromatography
(c) Liquid crystallization
(d) Mass chromatography
(e) Crystallization
(f) 4
(g) 3
(h) 2
(i) 1
(j) TLC
(l) Infrared Spectroscopy
(m) 1H
(n) 2H
(o) 13C
(p) 12C
(q) Increase
(r) Decrease
(s) Stay the same
(t) Erlynmeyer flask
(u) Grignard
(v) Aldol Condensation
(w) Claisen
11pts
Page 3. Chem. 216 Winter 2005
Name:________________________
III. For each of the reactions listed below, draw in the box provided the structure of the expected
major reaction product.
O
NaOH
O
H2O/Ethanol
∆
H3O+
workup
O
4pts
CH2CH3
+
H3C
4pts
+ enantiomer
IV. Draw the structures in the bigger box for the organic products containing a phenyl group
which are expected upon treatment of each of the following chemicals with D-PhMgBr,
followed by acidic work-up (3pts each). In the smaller box, provide the number of
expected carbon peaks in the 13C proton-decoupled spectra of each of the products (1pt each).
(b)
(a)
Dry ice
(CO2)
X22O
O
D
MgBr
D
X
O
H3C
CH3
O
H3C
(c)
CH3
(d)
24pts
total
Page 4. Chem. 216 Winter 2005
Name:________________________
V. For each of the reactions listed below, draw in the box provided the structure of the needed
reactant or the expected major reaction product.
+ Mg
2pts (a)
MgBr
H
-70oC
O
O
O
OTBS
H3CO
(b)
OCH3
No stereochem. needed
3pts
Hanna, I.;* Wlodyka, P. J. Org. Chem., 1997, 62, 6985-6990.
NC
CN
H3C
CH3
+
(c)
(2E, 4E)-2,4-hexadiene
H
H
3pts
Circle the dienophilic site that will react the fastest in the molecule shown below.
OCH3
(d)
2pts
10pts
Page 5. Chem. 216 Winter 2005
Name:________________________
VI. For the following reaction sequence, draw the correct structures in the box provided.
Benzene, reflux
O
Ph3P
+
Br
Ph = C6H5
O
3pts
“salt”
NaOCH3
in CH3OH
O
H
O2N
CH2Cl2
Room Temp.
C21H19PO2
3pts
+ NaBr + CH3OH
2pts
+ enantiomer
Major phosphorus containing fourmembered oxaphosphetane intermediate
3pts
Major Isomer: C10H9NO4 + Ph3P=O
2pts
+ enantiomer
Minor phosphorus containing fourmembered oxaphosphetane intermediate
3pts
Minor Isomer: C10H9NO4 + Ph3P=O
16pts
Page 6. Chem. 216 Winter 2005
Name:________________________
VII. On the basis of the spectroscopic information provided below, propose the structure of the
compound (C7H11NO2). Draw the proposed structure in the box. The number of peaks in the protoncoupled 13C spectra are listed above each singlet of the decoupled spectra as s = singlet, d = doublet, t
= triplet, and q = quartet.
IR
1
162.2mm
(singlet)
H NMR
36.2mm
(singlet)
solvent
ppm
Proton-decoupled 13C NMR
27.7
(t)
CDCl3
6pts
(s)
161.8
(s)
117.4
ppm
(s)
84.3
(q)
25.8
Page 7. Chem. 216 Winter 2005
Name:________________________
VIII. On the basis of the spectroscopic information provided below, propose the structure of the
compound (C10H9NO4). Draw the proposed structure in the box. The number of peaks in the protoncoupled 13C spectra are listed above each singlets of the decoupled spectra as s = singlet, d = doublet,
t = triplet, and q = quartet.
d
J=8Hz Expanded View
d
d
J=8Hz
12.3mm
8.1mm
1
H NMR
8.2mm
d
J=15Hz
J=15Hz
4.1mm
4.0mm
solvent
(d)
(d) 125.9
129.3
(quartet)
39.9
13
C proton decoupled NMR
(s)
6pts
125.5
(d)
141.3
(s)
170.0
(s)
147.9
(d)
140.7
ppm
TMS
Page 8. Chem. 216 Winter 2005
Name:________________________
IX. Based on the spectroscopic information provided below, draw the structure of the molecule in
the box. Molecular formula = C8H14O4.
IR: very strong peak at 1735cm-1.
1
13
H NMR
C proton decoupled NMR
q
t
d
6pts
s
CDCl3
q
Page 9. Chem. 216 Winter 2005
Name:________________________
X. Shown below are the 1H NMR spectra (only the aromatic H regions are shown) of the
three regio-isomers of nitro-phenol (2,3, or 4-nitro-phenol, C6H5NO3. In the boxes provided,
draw the structure of the isomer of nitro-phenol that would give each type of splitting pattern
of the ring protons.
OH
solvent
NO2
3pts
fuzzy
singlet
solvent
3pts
1H
1H
3pts
9pts
Page 10. Chem. 216 Winter 2005
Name:________________________
XI. The proton NMR spectrum of a mixture of acetone, Dimethylsulfoxide [DMSO: (CH3)2SO]
is integrated and results in step heights of 12 and 3ppm, respectively.
In what mole ratio are these two substances present? Provide your answer in the box shown
below. Report your ratios as whole numbers, not fractions.
:
Acetone : DMSO =
4pts
(a)
If we initially placed 8.23mg of DMSO into our NMR tube, how many mmoles of acetone would
we need to add to achieve the molar ratio determine from the integrations listed above?
Use the following atomic masses: C = 12, H = 1, O = 16, and S = 32 g/mol.
Shown all calculations
mmoles of acetone needed
(b)
3pts
O
H
O
+
(c)
OCH2CH3
+ Ph3P=O
Ph3P
O
3pts
How many different peaks would you expect to observe in the proton-decoupled 13C
NMR spectra of this molecule?
2pts (d)
12pts
Page 11. Chem. 216 Exam II. Winter 2005
Name:_____________________
XII. Show how many peaks you would expect to observe in the proton-decoupled 13C NMR
spectra of the following compounds. Indicate your answers in the box provided. Do not
count the 13C NMR peaks for the solvent and the internal standard, TMS. 3pts each. CH
3
H3C
CH3
O
H
CH3
(1)
O
(2)
H
CH3
H3C
CH3
CH3
O
H
H
O
H3C
(3)
CH3
(4)
CH3
HO
CH3
H
H3CO
CH3
(5)
OCH3
(6)
(7)
21pts
Page 12. Chem. 216 Exam II. Winter 2005
Name:_____________________
XIII. The 1H NMR and structure of ethyl vinyl ether is shown below. Using the coupling
constants provided, assign each NMR resonance with the appropriate set of protons in the
molecule by placing the appropriate label (Ha, Hb, etc) in the boxes provided.
2pts
2pts
1pt
1pt
triplet
2pts
quartet
Spin-Spin Constants
Ha
3
Ja,b = 15 Hz
Jc,b = 9 Hz
3
Ja,c = 2 Hz
3
e
O
d
Hc
Hb
8pts
Page 13. Chem. 216 Winter 2005
Name:________________________
XIV. On the basis of the spectroscopic information provided below, propose the structure of the
compound (C8H12O2). Draw the proposed structure in the box. The number of peaks in the protoncoupled 13C spectra are listed above each singlets of the decoupled spectra as s = singlet, d = doublet,
t = triplet, and q = quartet.
sextet
IR: strong peak at 1735 cm-1, medium peak at 2230 cm-1
1
quintet
singlet
H NMR
triplet
triplet
integrations
15.1
10.1
13
10.2, 10.1 15.2
C proton decoupled NMR
t
q
6pts
s
s
s
t t
q
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