39.
Which one of the following is not a possible product when a crossed aldol addition
reaction is carried out with ethanal and butanal as reactants?
OH
H
OOH
H
O
OH
H
OOH
H
O
OH
H
O
III III
IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
B
40.
Predict the product for the following reaction.
O
H
O
NaOH/H2O
+
OOO
III III
O
IV
O
V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
B
41.
Predict the major product for the following reaction.
O
H
O
H
O
NaOH/H2O
+
O
O
H
O
O
OH
OH
O
H
O
O
OH
H
O
III
IV V
O
O
H
O
III
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
D
42.
Provide the reactants that would give the following aldol condensation product.
O
H
O
H
O
OO
O
H
O
H
O
O
III
III IV
++
+
+
A)
I
B)
II
C)
III
D)
IV
E)
none of these
Ans:
C
43.
Provide the reactants that would give the following aldol condensation product.
O
H
H
O
H
O
OO
O
H
O
H
O
O
III
III IV
++
+
+
A)
I
B)
II
C)
III
D)
IV
E)
none of these
44.
Provide the reactants that would give the following aldol condensation product.
O
H
O
Ans:
A
45.
Provide the reactant(s) that would give the following aldol condensation product.
O
H
O O
H
O
O
H
O
O
O
O
O
O
O O
III III
IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
A
46.
Predict the major product for the following reaction.
OO
NaOH/H2O
O
O
O
O
I
II III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
Ans:
C
47.
Provide the reactant(s) that would give the following aldol condensation product.
H
O
H
H
O
O
H H
O O
III
H
HO
O
O
H H
O
III
IV
H
O O
V
+
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
A
48.
Provide the reactant(s) that would give the following possible aldol condensation
product.
O
H
O O
O O
III
OH O
III
H
O
OO
O
IV
V
+
A)
I
B)
II
C)
III
D)
IV
E)
V
49.
Which one of the following is a major product in a Claisen condensation?
A)
-keto ester
B)
-keto ester
C)
-hydroxy ester
D)
-hydroxyester
E)
-diketone
Ans:
B
50.
Explain why CH3ONa should not be used for Claisen condensation of ethylbutanoate.
Ans:
Use of CH3ONa will result in transesterification product.
Ans:
A
51.
Predict the major product for the following reaction.
O
O
O
OO
O
O
O
III
IV
O
OOH
V
O
OO
III
O O
1. NaOCH2CH3
2. H3O+
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
A
52.
Predict the major product for the following reaction.
O
O
1. NaOCH2CH3
2. H3O+
53.
Predict the major product for the following reaction.
1. NaOCH2CH3
2. H3O+
ethyl benzoate + ethyl butanoate
O
O
O
O
O O
O
OH O
O
O O
III
III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
Ans:
D
54.
Provide the structure of reactant (X) for the following reaction.
O
O
+ X1. NaOCH3
2. H3O+
O
O
O O
O O
O
H O
O
O
O
Br
O
O
O
O
O
O
III III IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
55.
Predict the product(s) for the following reaction.
1. NaOCH3
2. H3O+
methyl acetate + methyl propanoate
O
O O
O
O O
O
O O
O
O O
III III IV
A)
B)
C)
D)
V
E)
all of these
Ans:
E
56.
Provide the reactants that will yield the following compound as crossed Claisen
condensation product.
H O
O O
57.
Predict the product(s) for the following reaction.
O
O
O O
O
+1. NaOCH3
2. H3O+
OO
O O
O O
O
O
O
O
O
O
OO
I II III IV
A)
B)
C)
D)
V
E)
All of these
Ans:
A
58.
Provide the reactant(s) that will yield the following Claisen condensation product.
O
O O
59.
Predict the product(s) for the following reaction.
O
O
O
O1. NaOCH2CH3
2. H3O+
O
O
O
O
O
O
O
O
O
O
O
OH
O
O
III III
IV V
A)
B)
C)
D)
V
E)
V
Ans:
B
60.
Predict the product(s) for the following reaction.
1. NaOCH2CH3
2. H3O+
diethylheptanedioate
III III
IV V
O
O
OO
O
O
O
O
O
O
OH
O
O
A)
B)
C)
D)
V
E)
V
Ans:
A
61.
Which of the following compounds can be prepared using the Dieckmann condensation
O O
HO
O O
O
O
O O O
III III IV
A)
B)
C)
D)
V
E)
II & IV
Ans:
A
62.
Predict the product(s) for the following reaction.
1. NaOCH2CH3
2. H3O+
O
O
O
O
O
O
O
O
O
O
OH
O
O
O
O
O
O
O
III III
IV V
A)
B)
C)
D)
V
E)
V
Ans:
A
63.
Predict the product(s) for the following reaction.
O
O O
O
1. NaOCH2CH3
2. H3O+
O
O
OO
O
OO
O
O O
O
O
I II III IV
A)
B)
C)
D)
I&IV
E)
I & III
Ans:
E
64.
Provide a stepwise synthesis for the following compound starting with cycloheptene and
using the Dieckmann cyclization.
O
O
O
65.
Predict the product for the following Dieckmann-like cyclization.
O
O
O
1. NaOCH2CH3
2. H3O+
O
O
OO
O
O
O
O
OO
O
O
O
O
III III
IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
Ans:
B
66.
Predict the major product for the following reaction sequence.
O
O
O1. NaOCH2CH3
2. H3O+
O
H3O+
NaBH4/CH3OH
67.
Predict the product(s) for the following reaction.
O
1. LDA, -780C
2. CH3CH2Br
OOOO
III III IV
A)
B)
C)
D)
V
E)
none of these
Ans:
B
68.
Predict the product(s) for the following reaction.
1. LDA, –780C
2. CH3CH2I
2-methyl-3-pentanone
III III
OOO
O
IV
A)
B)
C)
D)
V
E)
none of these
Ans:
A
69.
Provide the reagents necessary to carry out the following conversion.
O
OH