Chapter Seventeen
1.
Which of the following compounds are isolated dienes?
III III
IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans.
B
2.
Which of the following compounds are conjugated dienes?
III III IV
A)
I
B)
II
C)
III
D)
IV
E)
II & IV
Ans.
E
3.
Which of the following compounds have conjugated double bonds?
III III IV V
4.
Which of the following compounds have isolated double bonds?
III III IV V
5.
Classify the following compounds as having cumulated, conjugated or isolated double
bonds?
CO
III III IV
O
O
V
6.
Which of the following compounds are cumulated dienes?
A)
4-methyl-1,3-heptadiene
B)
5-methyl-2,6-heptadiene
C)
2-methyl-2,4-heptadiene
D)
4-methyl-1,4-heptadiene
E)
5-methyl-2,3-heptadiene
Ans.
E
7.
Which of the following compounds are conjugated dienes?
A)
4-methyl-1,3-heptadiene
B)
5-methyl-2,6-heptadiene
C)
2-methyl-2,4-heptadiene
D)
4-methyl-1,4-heptadiene
E)
5-methyl-2,3-heptadiene
Ans.
A & C
8.
Which of the following compounds are isolated dienes?
A)
4-methyl-1,3-heptadiene
B)
5-methyl-2,6-heptadiene
C)
2-methyl-2,4-heptadiene
D)
4-methyl-1,4-heptadiene
E)
5-methyl-2,3-heptadiene
Ans.
B & D
9.
What is the IUPAC name for the following compound?
Cl
A)
1-chloro-1-methyl-2,5-cyclohexadiene
B)
3-chloro-3-methyl-1,4-cyclohexadiene
C)
6- chloro-6-methyl-1,4-cyclohexadiene
D)
2- chloro-2-methyl-1,3-cyclohexadiene
E)
None of these
10.
What is the IUPAC name for the following compound?
A)
(2E, 4Z)-2,4-hexadiene
B)
(2E, 4Z)-1,4-dimethyl-1,3-butadiene
C)
(2Z, 4Z)-1,4-dimethyl-1,3-butadiene
D)
(2Z, 4Z)-2,4-hexadiene
E)
None of these
Ans:
A
11.
What is the IUPAC name for the following compound?
A)
(2E,4Z,6E)–3,4,7,8–tetramethyl-2,4,6–heptatriene
B)
(2Z,4E,)–3,4,7–trimethyl-2,4,6–octatriene
C)
(2E,4Z,6E)–2,5,6,7–tetramethyl-3,5,7–heptatriene
D)
(2E,4Z)– 2,5,6–trimethyl-3,5,7–octatriene
E)
(2E,4E,)–2,5,6–trimethyl-2,4,6–octatriene
Ans:
E
Ans:
B
12.
What is the IUPAC name for the following compound?
Ans:
1-isopropyl-4-methyl-1,3-cyclopentadiene
13.
Provide the structure for (E)-1,3-pentadiene.
14.
Provide the structure for (Z)-2-methyl-2,4-hexadiene.
15.
Provide the structure for (1E,3Z)-1-methoxy-2-methyl-1,3-pentadiene.
H3CO
OCH3
H3CO
H3CO
III III
V
H3CO
IV
A)
I
B)
II
C)
III
D)
IV
E)
V
16.
Provide the structure for (3S,4E)-3-t-butyl-4-methyl-1,4-hexadiene.
17.
Which one of the following dienes is most stable?
A)
CH3CH=CHCH=CHCH3
B)
CH3CH=CHCH2CH=CH2
C)
CH2=CHCH2CH2CH=CH2
D)
CH2=CHCH(CH3)CH=CH2
E)
CH3CH=C=CHCH2CH3
Ans:
A
Ans:
A
18.
Which one of the following dienes is least stable?
A)
CH3CH=CHCH=CHCH3
B)
CH3CH=CHCH2CH=CH2
C)
CH2=CHCH2CH2CH=CH2
D)
CH2=CHCH(CH3)CH=CH2
E)
CH3CH=C=CHCH2CH3
19.
Which one of the following dienes is least stable?
III III IV
C
A)
I
B)
II
C)
III
D)
IV
Ans:
D
20.
Which one of the following dienes is most stable?
III III IV
A)
I
B)
II
C)
III
D)
IV
Ans:
C
Ans:
E
21.
Rank the following dienes in increasing order of stability (least to most).
III III IV
C
A)
I<IV<III<II
B)
III<II<I<IV
C)
IV<II<III<I
D)
II<IV<III<I
E)
I<III<II<IV
22.
Which one of the following dienes will have the least heat of hydrogenation?
III III
IV V
C
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
A
Ans:
C
23.
Which one of the following dienes will have the highest heat of hydrogenation?
III
III IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
24.
Rank the following dienes in order of decreasing heat of hydrogenation (most to least).
III III
IV V
C
25.
Rank the following dienes in order of decreasing heat of hydrogenation (most to least).
III III IV
Ans:
C
26.
Predict the product for the following reaction.
Br
(CH3)3COK
27.
Predict the product for the following reaction.
(CH3)3COK
Cl
28.
Provide the reagents necessary to carry out the following conversion.
29.
Provide the reagents necessary to carry out the following conversion.
OH
30.
Provide the reagents necessary to carry out the following conversion.
31.
Which one of the following represents the lowest energy -bonding molecular orbital of
1,3-butadiene?
III III IV
A)
I
B)
II
C)
III
D)
IV
Ans:
C
32.
Which one of the following represents the highest energy -antibonding molecular
orbital of 1,3-butadiene?
III III IV
A)
I
B)
II
C)
III
D)
IV
33.
How many -bonding molecular orbitals does 1, 3-pentadiene have?
A)
1
B)
2
C)
3
D)
4
E)
none
Ans:
B
34.
How many electrons does the HOMO of 1, 3-pentadiene have in its excited state?
A)
1
B)
2
C)
3
D)
4
E)
none
Ans:
A
Ans:
B
35.
How many electrons does the HOMO of 2, 4-hexadiene have in its ground state?
A)
1
B)
2
C)
3
D)
4
E)
0
36.
How many electrons does the LUMO of 2, 4-hexadiene have in its ground state?
A)
1
B)
2
C)
3
D)
4
E)
0
Ans:
E
37.
Which one of the following represents the HOMO of 1,3, 5-hexatriene?
III III
IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
A
Ans:
B
38.
Which one of the following represents the LUMO of 1,3, 5-hexatriene?
III III
IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
39.
Which major product(s) are formed for the following reaction?
HI
I
I
I
I
III III IV
I
V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
A
Ans:
D
40.
Which one of the following compounds is not a product of reaction between 1,3-
butadiene and HBr?
A)
(S)-3-bromo-1-butene
B)
(R)-3-bromo-1-butene
C)
(E)-1-bromo-2-butene
D)
(Z)-1-bromo-2-butene
E)
(Z)-2-bromo-2-butene
41.
Predict the product(s) for the following reaction.
HCl
42.
Predict the possible major products for the following reaction.
HBr
Ans:
E
43.
Predict the possible products for the following reaction and provide a curved arrow
mechanism for the formation of these products.
HBr
44.
Provide the structure of the 1,4 addition product for the reaction of 1,3-hexadiene with
Br2/CCl4?
45.
Provide the structure of the 1,2 addition product for the following reaction.
Br2
CCl4
46.
A thermodynamically-controlled reaction will yield :
A)
the most stable product.
B)
the product whose formation requires the smallest free energy of activation.
C)
the product that can be formed in the fewest steps.
D)
the product that is formed at the fastest rate.
E)
None of these.
Ans:
A
47.
A reaction under kinetic control will yield :
A)
the most stable product.
B)
the product that can be formed in the fewest steps.
C)
the product whose formation requires the smallest free energy of activation.
D)
the product with the greatest potential energy.
E)
None of these
48.
Predict the major product for the following reaction.
HCl
00C
49.
Predict the major product for the following reaction.
HCl
400C
Ans:
C
50.
Provide the structure for 1,2 addition product for the following reaction and explain why
it is a major product rather than 1,4 addition product.
HBr
400C
51.
Predict the major product for the following reaction and explain why it is major product.
HBr
400C
52.
Predict the major product for the following reaction.
HCl
00C
53.
What is the correct classification of the following pericyclic reaction?
heat
A)
electrophilic addition
B)
sigmatropic rearrangement
C)
cycloaddition
D)
electrocyclic reaction
E)
C & D
Ans:
B
54.
What is the correct classification of the following pericyclic reaction?
A)
electrophilic addition
B)
sigmatropic rearrangement
C)
cycloaddition
D)
electrocyclic reaction
E)
C & D
Ans:
D