CHEM 233, Fall 2014
Ian R. Gould
FINAL EXAM
PRINTED
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PRINTED
LAST NAME
ASU ID or
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• PRINT YOUR NAME ON EACH PAGE!
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work on blank pages will not be graded...
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8_____________/63
• DON'T CHEAT, USE COMMON SENSE!
Total (incl Extra)________/375+5
Extra Credit_____/5
H
He
Li Be
B
N
O
F
Ne
Na Mg
Al Si P
S
Cl
Ar
Ga Ge As Se Br
In Sn Sb Te I
K
Ca
Rb Sr
Cs Ba
Sc Ti V
Y
Cr Mn Fe Co Ni Cu Zn
Zr Nb Mo Tc Ru Rh Pd Ag Cd
Lu Hf Ta W
small range
range of values
broad peak
Re Os Ir Pt Au Hg
O H
C N
N H
C O
C
Tl Pb Bi Po At
H
C
C
N
2850–2960
Rn
Me/Et
1600–1660
11
220 O
10
200
R C OH
~2.7
Approximate Coupling
Constants, J (Hz), for
1H NMR Spectra
H H
H
1680
~7
H
OR
H
~10
C C
1735
CH
~8
H
1600
O
2000
H
O
C CH3
–H2C NR2
7
140
6
120
5
100
R2C
Aromatic
CR2
C CH
4
80
3
60
RC
CR
Alkyl
3Y > 2Y > 1Y
2
40
–OCH2–
R C N
H
~15
C C
1500
–OCH2–
C CH2
8
160
~2
H
NR2
1650
NMR Correlation Charts
H
H
C
1710
~2
C C
O
Aromatic Ar H
mainly 8 - 6.5
O
C
t-Bu/Me
O
C
2500
9
180
~1.1
~2.9
N
–H2C X
(δ, ppm)
~0.95
i-Pr/Me
C C
2200
3000
O
C H
Et/Me
~2.6
C
C
C
amine R NH2 variable and condition
alcohol R OH dependent, ca. 2 - 6 δ
O
R C OH
~1.4
H
C
O
C O H
3500
~0.9
C
broad ~3000
(cm-1)
Me/Me
H
broad with spikes ~3300
broad ~3300
Me/Me
O
2200
O H
H/Me
Xe
C
2720–2820
2 peaks
3000–
3100
N H
Kr
H
C
3300
~1.0
Infrared Correlation Chart
H
Gauche
Eclipsing
H/H
usually
strong
O
C H
Interaction Energies, kcal/mol
1
20
0
0
Alkyl 3Y > 2Y > 1Y
C X
C NR2
CHEMISTRY 233, Fall 2014 FINAL EXAM
-2-
NAME
Question 1 (15 pts.) Give the IUPAC name for the following. Specify stereochemistry
as appropriate.
Br
Question 2 (18 pts.) Give the product of the following Lewis acid/base reaction. Indicate the
Lewis/base and whether they are also Bronsted acids/bases, give the curved arrow pushing
showing bond making/breaking and BRIEFLY explain why the reactions would be exothermic
or endothermic.
O
H2C
CH2
+
OH
Question 3 (10 pts.) For the following cyclohexane, draw the lowest energy chair conformation
(only)
Et
Me
Br
Question 4 (16 pts.) Give the Lewis structure for (2R)-bromo-(3R)-methylpentane, with
stereochemistry indicated using wedged/dashed bonds as appropriate, AND, draw a Lewis
structure of its enantiomer (clearly indicate which structure is which)
CHEMISTRY 233, Fall 2014, FINAL EXAM
-3-
Question 5 (44 pts) Solvolysis of both bromides A and B form the same ether, as shown below
a) Draw a full -curved arrow-pushing mechanism for each reaction, at each intermolecular step
indicate the Lewis acid and base and whether they are also Bronsted acids and bases. Include
all reasonable resonance contributors for intermediates as appropriate
Br
OMe
Br
MeOH
MeOH
B
A
heat
heat
b) Draw a properly labelled reaction energy diagram for BOTH reactions on the SAME diagram,
CLEARLY indicate which diagram refers to which reaction
CLEARLY INDICATE THE ACTIVATION ENERGY FOR THE RATE DETERMINING
STEP FOR EACH REACTION
c) BRIEFLY explain which reaction would be faster, A or B
-4-
CHEMISTRY 233, Fall 2014 FINAL EXAM
NAME
Question 6 (16 pts.)
1. Determine whether the following structures are identical, enantiomers or diastereomers
2. Identify any meso compounds.
3. Give the absolute configuration at each chiral (asymmetric) center
Br
HO
C C
H
H
OH
Br
Br
HO
Br
C C
H
H
OH
Question 7 (22 pts.) For the following two reactions
a) give the curved arrow pushing showing bond making/breaking and indicate the Lewis
acids/bases (LA/LB) and whether they are also Bronsted acids/bases (BA/BB)
b) one of these reactions is endothermic, the other is exothermic, indicate which is which and give
a brief explanation for WHY each reaction is exothermic or endothermic
H
H B
H
H
+
OH
H B
+
A
H O
H
H
H
+
H B
H
OH
B
H B OH
H
Question 8 (24 pts.)
a) Draw pictures of the wavefunctions of the molecular orbitals requested, on the
molecules. In each case indicate the A.O.'s used to make the M.O.'s.
H
H
C
O
H
H
C
H
C-O π orbital
C-C σ orbital
indicated by the arrow
O
H
O-H σ* orbital
CHEMISTRY 233, Fall 2014 FINAL EXAM
-5-
NAME
Question 9 (70 pts.) Give the missing major ORGANIC PRODUCT for each reaction
a) Show all stereochemistry as appropriate, identify any MESO compounds
b) Briefly explain whether and why a solution of the product would be optically active or not
c) assign each reaction as addition, elimination, substitution or rearrangement
Cl
CH3O– +Na
a)
DMF
HBr
b)
HBr
c)
ROOR
1. BH3.THF
d)
2. –OH/H2O2
Ph
Ph
Me
Me
e)
f)
H2
Pd/C
Br2
hν
g)
Br2
MeOH (solvent)
-6-
CHEMISTRY 233, Fall 2014, FINAL EXAM
NAME
Question 10 (32 pts). For nucleophiles going down the periodic table, nucleophilicity and basicity
follow exactly the same trend in polar APROTIC solvents, but follow OPPOSITE trends in polar
PROTIC solvents. Use this information to answer the following questions.
a) Draw a reaction energy diagram for BOTH reactions A and B on the SAME diagram, clearly
indicate BOTH activation energiess AND both reaction exothermicities. Explain which reaction
would be faster (both reactions are exothermic because the tosylate anion -OTs is very stable, and
ignore the Hammond postulate).
Na
Cl
OTs
Cl
A
+ Na
OTs
DMF
B
Na
Br
DMF
OTs
Br
+
Na
OTs
c) Now do the same for reactions C and D below, and explain why the nucleophilities are
different in polar protic versus polar aprotic solvents (both reactions are exothermic and
again ignore the Hammond postulate)
Na
Cl
Cl
OTs
+ Na
OTs
C
MeOH
D
OTs
Na
Br
MeOH
Br
+
Na
OTs
NAME
-7-
CHEMISTRY 233, Fall 2014 FINAL EXAM
Question 11 (38 pts.)
a) For the reaction shown, give a curved arrow mechanism and indicate the Lewis/Bronsted acids
and bases at each step as appropriate, and indicate the the number of steps and transition states
associated with your mechanism
H2O (solvent)
HCl cat.
HO
how many steps are there in your mechanism? ______________
how many transition states are associated with your mechanism? ______________
b) Draw a reaction energy diagram, indicate the positions and relative energies of the starting
materials, intermediates and products and ALL TRANSITION STATES, but Do not draw the
structures of any transition states
c) On your diagram, indicate the activation energy for each step in the mechanism and the
reaction exothermicity and clearly indicate the rate determining step
-8-
CHEMISTRY 233, Fall 2014 FINAL EXAM
NAME
Question 12 (28 pts.)
a) Rank the three indicated C–H bonds A, B and C in order of increasing bond dissociation energy.
Draw an energy diagram for cleavage of all THREE bonds and give a BRIEF explanation for your
choice of ranking
C
H
<
<
lowest
BDE
highest
BDE
A
H
H
B
b) For the structure below, give the curved arrow pushing and the products of homolytic cleavage
for the C-H bond that has been added to the line-angle structure (include all resonance contributors
as appropriate)
H
Question 13 (14 pts.) Give the hybridization of the NITROGEN atom in acetonitrile (structure given
below), and show that you understand the meaning of the hybridization assignment by making a
small table that summarizes all of the valence hybrid (and any unhybridized) atomic orbitals
associated with this nitrogen atom, and state how they are used (e.g. used to make a sigma bond
to the chlorine, I know there is no chlorine in the structure, this is just to show you what do to)
H3C
C
N
Extra Credit (5 pts.) Which of the following drugs resulted in terrible birth defects in Europe
in the 1960s?
ibuprofen
thalidomide
ketamine
thebaine
-9-
CHM 233, Fall 2014, Final Exam
NAME
Question 14 (28 pts) Provided are spectra for a compound with molecular formula C6H12O2
a) Give the degrees of unsaturation
________________
b)On the infrared spectrum, indicate the peaks that identify the functional groups in the
molecule (including C(sp3)-H). Indicate BOTH the functional group, and where
appropriate, the specific BOND in the functional that corresponds to the peak.
959
1461
2856
1381
2997
1729
1109
1198
c) draw the structure and clearly indicate which hydrogens correspond to which
signals in the proton nmr spectrum (only)
6H
doublet
3H
triplet
2H
quartet
1H
multipet