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Name___________________________________
Final Exam
143 total points
1. Give the systematic name for each of the following compounds (5 pts).
CH3
a.
Br
CH3
b.
CH3CH2CH2NH2
CH3
c.
d.
e.
CH3
H
CH2CH3
C C
CH3
CH2CH2 Cl
C C
H
CH3
CH3
CH3CH2CHCH2CHCH2CH3
CHCH3
CH3
2. Draw the Lewis structure for each of the following compounds. Include formal
charges (2 pts).
a.
CH3CH2CH2COO
b.
CH3CH2NHCOCH3
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3. Which of the following is a stronger acid (2 pts).
a.
O
CH3CHCH2COH
Br
or
O
CH3CHCH2COH
Cl
b.
O
CH3CHCH2COH
Cl
or
O
CH3CH2CHCOH
Cl
4. Circle true or false for each of the following (8 pts):
a. Ethylamine is a stronger base than ethyl alcohol.
T or F
b. HF is a stronger acid than HCl.
T or F
c. Cyclohexene has one degree of unsaturation.
T or F
d. (R)-2-bromobutane and (S)-2-bromobutane are constitutional isomers.
T or F
e. 2,4-dimethylpentane has 2 chiral centers.
T or F
f. An SN2 reaction has one transition state.
T or F
g. An exergonic reaction has a negative ΔG.
T or F
h. CH3MgBr is a Gillman reagent.
T or F
5. Answer the following (4 pts):
a. Finish drawing the perspective formula for (S)-2-bromobutane.
Br
CH2CH3
b. How many possible stereoisomers are there for 2,3-dibromopentane?
c. Define a racemic mixture.
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d. Which of the following is not true about sp3, sp2, and sp hybridization?
1. sp2 has more s character than sp3
2. sp2 is a hybrid of 2 orbitals
3. sp has a larger bond angle than sp2 bond angle
4. sp2-sp2 bond length is shorter than sp3-sp3 bond length
5. None of the above.
6. Answer the following questions about the molecule below (Diflucan®) (4 pts).
b.
a.
c.
d.
a. How many degrees of unsaturation are there in Diflucan®.
b. Indicate the hybridization at each C, N, and O marked by an arrow.
a.______
b.______ c. ______ d.______
c. Circle all chiral carbons in Diflucan®.
7. Answer the following questions (6 pts):
a. Draw the most stable conformation of the molecule below. Calculate the
strain.
CH3
CH3
CH3
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b. Write the ground-state electron configuration for oxygen.
c. How many valence electrons does nitrogen have?
d. How many degrees of unsaturation are there in C13H12F2N6O?
e. Write the following condensed structure as a Kekule structure:
(CH3)2CHCH2CH2OH
8. Show all mechanisms and major products of the following reactions (9 pts):
H3C
a.
b.
CH CH2
+ H2O
CH3CH CHCH2CH3
H2SO4
Br2
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c.
H2O, H2SO4
HgSO4
CH3CH2C CH
9. Show the major product of the following reaction and the stereochemistry
obtained (6 pts).
a.
NBS
H2O/DMSO
b.
1. BH3/THF
2. H2O2, -OH, H2O
c.
1. O3
2. Zn, H3O+
10. Assuming initiation has already occurred, show the propagation steps of the
following reaction. Show only mechanisms leading to the most stable radical
intermediate, any resonance that occurs, and mechanisms leading from the most
stable radical intermediate to the product (3 pts).
Initiation
Br Br
Br
Br
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11. Answer the following questions (4 pts):
a. Are the following molecules enantiomers, diastereomers, or the same?
H Br
H Br
HO H
H OH
b. Which would be a better solvent for an SN2 reaction- DMF or CH3OH?
c. The best nucleophile in a substitution reaction at a primary carbon:
CH3CO2
-
SH
-
OH
H2O
d. Is the following reaction an oxidation, reduction, or neither?
1. BH3/THF
2. H2O2, -OH, H2O
12. Show how the following compound could be prepared using the given starting
material and any necessary reagents. Show all mechanisms (5 pts).
HC CH
?
O
CH3CH2CH2CH
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13. Provide structures for the reactants, intermediates, or products, as indicated, in the
following reactions. Draw the structures in the boxes provided (7 pts).
1. Li, pentane
a.
CH3I
CH3CH2I
2. CuI
SOCl2
b.
Cl
pyridine
Mg
D2O
c.
Br
ether
Br
d.
14. Answer the following questions about (2R,3S)-dibromobutane (2 pts).
a. Draw its most stable Newman projection sighting down the C2-C3 bond.
b. (2R,3S)-dibromobutane is:
1.
2.
3.
4.
optically active
racemic
dextrorotary
a meso compound
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15. Label each of the compounds below as (4 pts):
a.
b.
c.
d.
conformational isomers
stereoisomers
constitutional isomers
identical
OH
OH
Br
Br
CH3
CH3
1.
3.
OH
OH
H
H
CH3
H
CH3
H
H3C
2.
4.
H
CH3 H
H
H
CH3
H
H
H
CH3
Cl
H
H
H
16. Circle the correct answer to each of the following questions (7 pts):
a. When an organic molecule is irradiated with ultraviolet radiation, the
energy absorbed by the molecule corresponds to:
1. the amount necessary to increase the molecular motions in
functional groups
2. the amount necessary to excite electrons from one molecular
orbital to another
3. the amount necessary to “flip” the spin of atomic nuclei
4. the amount necessary to strip the molecule of one electron to
generate a radical cation
b. The amount of energy in electromagnetic radiation is related to the
frequency and wavelength of the radiation. High energy radiation like
gamma rays is of:
1.
2.
3.
4.
low frequency and short wavelength
low frequency and long wavelength
high frequency and short wavelength
high frequency and long wavelength
H
Cl
H
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c. For the Diels-Alder cycloaddition reactions to take place most rapidly and
in highest yield the dienophile must:
1.
2.
3.
4.
be substituted with electron-withdrawing groups
be able to adopt and s-trans conformation
be substituted with electron-donating groups
be able to adopt an s-cis conformation
d. Electrophilic addition reactions that occur at high temperature and/or long
reaction times (reversible conditions) are said to be under:
1.
2.
3.
4.
1,2 control
kinetic control
1,4 control
thermodynamic control
e. For a nucleus to exhibit nuclear magnetic resonance phenomenon, it must
be magnetic. Magnetic nuclei include:
1.
2.
3.
4.
all nuclei with even numbers of protons and neutrons
all nuclei with odd numbers of protons
all nuclei with odd number of neutrons
both 2 and 3
f. Which of the following statements best describes the base peak in a mass
spectrum?
1. The peak from the most stable radical.
2. The peak from the species that has the isotope with the
highest atomic number.
3. The peak of the highest intensity.
4. The peak from the molecule minus an electron.
g. The amount of energy in infrared light corresponds to:
1. the amount necessary to increase the molecular motions in
functional groups
2. the amount necessary to excite electrons from one
molecular orbital to another
3. the amount necessary to “flip” the spin of atomic nuclei
4. the amount necessary to strip the molecule of one electron
to generate a radical cation
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17. Consider the reaction below to answer the following questions (5 pts).
CH3
CH3
C Br
CH3
H2O
CH3
A
CH3
C OH
CH3
B
CH3
CH2
+
CH3
C
a. Compound B is the:
1.
2.
3.
4.
SN2 product.
SN1 product.
E2 product
E1 product
b. Compound C is the:
1.
2.
3.
4.
SN2 product
SN1 product
E2 product
E1 product
c. Doubling the concentration of water in this reaction:
1.
2.
3.
4.
causes the reaction mechanism to change
halves the rate of the reaction
has no effect on the rate of reaction
doubles the rate of reaction
d. Write a complete reaction mechanism for the formation of Compound C in
this reaction.
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18. Answer the following questions about the compounds below (4 pts):
Br
A
B
a. How many signals would you expect each molecule to have in a 13C NMR
spectra?
A. _____
B. ______
b. How many types of nonequivalent protons are there?
A. _____
B. ______
c. Which molecule would absorb UV radiation at a higher wavelength?
d. Why?
19. The following molecules may be prepared using the Diels-Alder reactions. Write
the structure for the starting diene and dienophile necessary to prepare each
molecule and label them (4 pts).
CH3
a.
H
CH3
O
b.
O C
CH3
20. Tell whether the Diels-Alder product in B above is endo or exo (1 pt): ________
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21. Determine the structure of the compound that gives rise to the following mass
spectra (a), infrared spectra (b), and 1H NMR spectra (c). Label the peaks in the
1
H NMR spectra (3 pts).
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22. Determine the structure of the compound that gives rise to the following mass
spectra (a), infrared spectra (b), and 1H NMR spectra (c). Label the peaks in the
1
H NMR spectra (3 pts).
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23. Provide correct IUPAC names for each of the following compounds (5 pts):
a.
H3C
b.
OH
Br
c.
O
OH
d.
Cl
Br
e.
CH3
Br
24. For each molecule below, predict whether the molecule will be expected to show
aromatic character (circle yes) or not (circle no) (4 pts).
yes or
yes or
no
yes or
no
yes or
no
no
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25. For each of the compounds below, tell how many signals you would expect the
molecule to have in its 1H NMR and its 13C NMR spectra (8 pts).
a.
CH3
CH3 C CH2CH3
CH3
b.
1H
NMR:
13C
1H
NMR:
13
1
c.
NMR:
C NMR:
H NMR:
13C
NMR:
H NMR:
13C
NMR:
Br
CH3
d.
H
CH2CH3
1
H
26. Refer to the structure below to answer the following questions (2 pts):
O
a
C
CH3
CH3
C
CH
CH3
CH3
CH3
b
a. What is the splitting pattern for the hydrogens labeled a?
1. septet
2. quartet
3. triplet
4. doublet
5. singlet
6. sextet
b. What is the splitting pattern for the hydrogens labeled b?
1. septet
2. quartet
3. triplet
4. doublet
5. singlet
6. sextet
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27. Match the following bond types to the region of the infrared spectrum to which
their absorptions occur. Place the letter of the region to the blank to the left of the
bond-type (4 pts).
a. ~3450 cm-1 b. ~1700 cm-1 c. ~2100cm-1 d. ~1200 cm-1 e. ~1600 cm-1 f.~2900 cm-1
1.
C O
3.
C C
2.
O H
4.
C C
28. Answer true or false to each of the following questions regarding the compounds
below (6 pts):
Br
A
B
a. Compound A follows Huckels Rule. T or
F
b. Compound A is aromatic.
F
T
or
c. Each carbon on B is sp2 hybridized. T
or
F
d. Compound B is aromatic.
or
F
T
e. The lowest energy molecular orbital of Compound A has no nodes. T
or
F
f. The lowest energy molecular orbital of Compound B has no nodes. T
or
F
29. Name the compound below. Draw the possible products resulting from the
addition of 1 equivalent HBr to the compound below. Circle the major product of
the reaction (5 pts).
CH CH CH CH2
Name:________________________
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30. Show the structure, including stereochemistry, of the product from the DielsAlder reaction with the diene in question 29 and the dienophile shown below (2
pts):
O
CH
HC
O
31. Consider the reaction below to answer the following questions (9 pts):
Br
Br
+
A
HBr
B
C
D
a. The kinetically controlled product in this reaction is ______.
b. The product that results from 1,4- addition is _____.
c. The nucleophile in the first step of the reaction is _____.
d. The electrophile in the second step of the reaction is _____.
e. Draw the resonance hybrid of the common intermediate.
f. Draw a representative reaction coordinate diagram for the formation of C
and D (in one diagram). Make sure to label any transition state(s),
intermediate(s), products, and axis.