Page 1
1.
What would be the name of the following?
CH3
A)
5-cyclopentyl-1-methylcyclononane
B)
cis-1-cyclopentyl-5-methylcyclodecane
C)
cis-5-methyl-1-cyclopentylcyclododecane
D)
trans-cyclopentyl-5-methylcyclodecane
E)
(5-methylcyclodecyl)cyclopentane
2.
Which of the following isomers would you expect to have the lowest heat of
combustion? (i.e., be most stable)
A)
cis-1,2-dimethylcyclohexane
B)
trans-1,3-dimethylcyclohexane
C)
cis-1,4-dimethylcyclohexane
D)
cis-1,3-dimethylcyclohexane
E)
All should have the same heat of combustion.
3.
Terpenes can be considered to be built up from what units?
A)
B)
C)
D)
E)
Page 2
4.
Which of the following compounds has the highest heat of combustion per CH2
group?
A)
cyclopropane
B)
cyclobutane
C)
cyclopentane
D)
cyclohexane
E)
All have equal Hcombustion.
5.
What is the correct IUPAC name for the following molecule:
A)
1-ethyl-2-methylhexane
B)
2-ethyl-1-methylcycloheptane
C)
4-ethyl-5-methylcyclohexane
D)
1-ethyl-2-methylcyclohexane
E)
1-methyloctane
Page 3
6.
Which would be the most stable conformation of
trans-1-methyl-3-isopropylcyclohexane?
A)
B)
CH(CH3)2
CH3
H
H
C)
CH(CH3)2
H
H3C
H
D)
CH(CH3)2
H
CH3
H
E)
H
CH3
H
CH(CH3)2
7.
Which one of the following cyclic alkanes has the greatest tendency to have a planar
ring?
A)
cyclopropane
B)
cyclobutane
C)
cyclopentane
D)
cyclohexane
E)
None of the above are planar.
Page 4
8.
What would be the proper name of the following:
CH3
H
H
(CH3)3C
A)
cis-1-tert-butyl-4-methylcyclohexane
B)
trans-1-tert-butyl-4-methylcyclohexane
C)
axial,equatorial-1-tert-butyl-4-methylcyclohexane
D)
cis-1-isopropyl-4-methylcyclohexane
E)
trans-1-isopropyl-4-methylcyclohexane
9.
The most stable conformation of cis-1,3-dimethylcyclohexane has how many hydrogen
atoms in axial positions?
A)
4
B)
5
C)
6
D)
8
E)
None of the above.
10.
Which of the following disubstituted cyclohexanes could exist in a conformation that
has both groups equatorial?
A)
cis-1,3-dimethylcyclohexane
B)
cis-1,4-dimethylcyclohexane
C)
trans-1,3-dimethylcyclohexane
D)
cis-1,2-dimethylcyclohexane
E)
All or none can have both groups equatorial.
Page 5
11.
Which of the following correctly represents cyclopropylcyclohexane?
A)
B)
C)
D)
E)
None of the above.
Page 6
12.
Which of the following ring systems belongs to the class of compounds called steroids?
A)
B)
C)
D)
E)
Page 7
13.
Which of the following could be classified as a terpene?
A)
B)
CHO
C)
O
D)
O
E)
O
Page 8
14.
Which of the following could have both methyl groups in an equatorial orientation?
A)
CH3
CH3
B)
CH3
CH3
C)
CH3
CH3
D)
H3C
CH3
E)
CH3
H3C
15.
Which of the following compounds has the lowest heat of combustion per CH2 group?
A)
cyclopropane
B)
cyclobutane
C)
cyclopentane
D)
cyclohexane
E)
All have equal Hcombustion.
Page 9
16.
Which, if either, of the two isomers of the compound shown below would be more
stable?
(trans) (cis)
A)
Cis is more stable.
B)
Trans is more stable.
C)
Both are equally stable.
D)
Neither is stable.
E)
There is no way to predict this.
17.
Although five- and six-membered rings are generally the most stable, why is
cyclopentane less stable than cyclohexane?
A)
The angles in cyclopentane deviate significantly from the tetrahedral angle.
B)
Five-membered rings have trans annular interactions.
C)
Five-membered rings have eclipsing hydrogens.
D)
Planar cyclohexane has bond angles closer to 109.
E)
Larger rings are always more stable than smaller rings.
18.
Which of the following correctly shows the Newman projection along a C-C bond in
cyclohexane? (the squiggles indicate where the rest of the ring is attached)
H
H
CH2
H
H
CH2
H
HH
H
CH2
CH2
H
CH2
H
H
H
CH2
H
H
H
H
CH2
CH2
H
H
H
CH2
CH2H
A B C
D E
A)
A
B)
B
C)
C
D)
D
E)
E
Page 10
19.
Which of the following cyclic alkanes can be ring-opened under hydrogenation
conditions?
cyclic hydrocarbon H2
Pd linear hydrocarbon
A)
cyclopropane
B)
cyclobutane
C)
cyclopentane
D)
cyclohexane
E)
more than one of these
20.
Which of the following statements about conformations of methylcyclohexane is true?
CH3CH3
A)
The energy barrier to interconvert these is too high to be achieved at room
temperature.
B)
The two forms are in equilibrium and are present in equal amounts at room
temperature.
C)
The two forms are not in equilibrium but are present in equal amounts at room
temperature.
D)
The two forms are in equilibrium but are not present in equal amounts at room
temperature.
E)
The two forms are not in equilibrium and are not present in equal amounts at room
temperature.
21.
Cyclohexanes exhibit a higher_______than their straight-chain analogs. (Choose the
correct answer)
A)
boiling point
B)
melting point
C)
density
D)
All of these are correct.
E)
Two of these are correct.
Page 11
22.
Which conformation of cyclohexane experiences the most transannular strain?
A)
Chair
B)
Planar
C)
Boat
D)
Twist boat
E)
All of these are stable.
23.
Which of the following is not in its most stable conformation?
A)
Cl
CH3
B)
ICH2CH3
C)
H3COCH3
D)
HOOC
Br
E)
All of these are in their most stable conformation.
24.
What is the potential energy change to convert from a twist-boat to boat conformation?
A)
–14 Kcal/mol
B)
0 Kcal/mol
C)
1.4 Kcal/mol
D)
14 Kcal/mol
E)
45 Kcal/mol
Page 12
25.
Which of the following structures represent cis-1,4-dimethylcyclohexane?
H
CH3
CH3
H
ICH3
H
CH3
H
II CH3
H
H
H3C
III
A)
I & II
B)
I & III
C)
II & III
D)
All of the above.
E)
None of the above.
26.
What is the correct structure of 2-methyl-1,3-butadiene?
A)
B)
C)
D)
E)
None of the above.
27.
Steroids frequently function as _____________, which are regulators of biochemical
activity.
A)
proteins
B)
nucleic acids
C)
hormones
D)
fatty acids
E)
triglycerides
Page 13
28.
What is the most stable conformation of trans-1-fluoro-4-methylcyclohexane?
A)
F
CH3
B)
CH3
F
C)
F
CH3
D)
F
CH3
E)
CH3
F
29.
What is the correct name for the following molecule?
CH2CH2CH3
Cl
H3C
A)
1-chloro-2-methyl-4-propylcyclopentane
B)
2-chloro-1-methyl-4-propylcyclopentane
C)
1-chloro-5-methyl-3-propylcyclopentane
D)
5-methyl-1-chloro-3-propylcylopentane
E)
1-chloro-3-propyl-5-methylcyclopentane
Page 14
30.
How many isoprene units are in eudesmal?
CH2
CH3
CH3
CH3
OH
Eudesmol
A)
0
B)
1
C)
2
D)
3
E)
Unable to determine
Page 15
Answer Key