Test Problems for Chapter 18 With Answers
27
Page 1 1. Which product would you not expect in the crossed aldol reaction between acetaldehyde and propionaldehyde? H 3 C C O H CH 2 C O H H 3 C ? cat. NaOH H 2 O + A) CH 2 C O H H 2 C C OH H H 3 C B) CH C O H H 3 C C CH 3 H OH C) CH 2 C O H H 3 C C OH H D) CH C O H H 3 C C OH H CH 3 E) CH C O H H 2 C C OH H CH 3 H 3 C Ans: B
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Transcript of Test Problems for Chapter 18 With Answers
Page 1
1. Which product would you not expect in the crossed aldol reaction between acetaldehyde and propionaldehyde?
H3C C
O
H CH2C
O
HH3C?
cat. NaOH
H2O
+
A)
CH2 C
O
HH2C C
OH
H
H3C
B)
CH C
O
HH3C C
CH3
H
OH C)
CH2 C
O
HH3C C
OH
H D)
CH C
O
HH3C C
OH
H CH3 E)
CH C
O
HH2C C
OH
H CH3
H3C
Ans: B
Page 2
2. What organic molecule would you expect to be present in significant amounts under the following conditions?
O
CH3H
cat. KOD?
only (S) enantiomer
excess D2O
A)
DO
CH3
HOH
B)
O
CH3D
C)
O
D)
OCH3
D
racemic E)
OCD3
D
racemic Ans: D
Page 3
3. What reactants would be used to produce cinnamaldehyde?
CHO?
cat. NaOH H2O
A)
CHO+ CH3CHO
B)
CHO
HC
CHO
O
+
C)
CH3
O
+ CH2=O
D)
OCHO+
E)
CHO
H3CC
CHO
O
+
Ans: A
Page 4
4. What would you expect to result from the following reaction?
O?
1. (CH3)2CuLi
2. H2O
A)
O
B)
OH
C)
OH
CH3
D)
O
E)
O
Ans: A
Page 5
5. Indicate to which side, if any, the following equilibrium lies:
O OH+ or HO-
A) To the right B) To the left C) Equally to right and left D) Cannot be predicted E) Major product is an enol or enolate ion, respectively
Ans: A
Page 6
6. What would be the expected product of the following reaction?
CH3
O
HC
CH2
O
CH3+CH3O- Na+
CH3OH?
heat
A)
O
B)
O
C)
O
D)
O
E)
O
Ans: A
Page 7
7. What major product would you expect from the following reaction?
O
Na+ -OCH3CH3OH, heat
?CH2=O
A)
HO OCH3
B)
CH2
C)
O
CH3
D)
CH2
O
E)
O
Ans: D
8. Which proton in the following molecule is the most acidic?
CH2 CH2 C
O
H
H
H
2
543
1
A) 1 B) 2 C) 3 D) 4 E) 5 Ans: D
Page 8
9. What product is formed in the aldol condensation of propanal?
CH3CH2CHOKOH
H2O?
A)
CHO
O
B)
CHO
OH
C)
OH
O
D)
HO CHO
E)
CHO
OH
Ans: B
10. To which side, if any, would the following equilibrium lie?
H3C C
O
CH3H3C C
OH
CH2
A) To the left D) Reaction cannot occur at all B) To the right E) Equilibrium favors a different
product. C) Equally to the left and right
Ans: B
Page 9
11. To which side, if any, would the following equilibrium lie?
H3C C
O
CH3H3C C
O
CH2
+ H2O- Na+
+ NaOH
A) To the left D) Reaction cannot occur at all B) To the right E) Equilibrium favors a different
product. C) Equally to the left and right
Ans: B
Page 10
12. Which major product would you expect when the following diketone undergoes aldol cyclization in base, followed by acid?
O ONaOCH2CH3 H3O+
A)
O
H3C
B)
O
O
C)
CH3
O
CH3
D)
O
CH3
E)
CH3O
Ans: A
Page 11
13. Which set of reagents would be needed for the following conversion?
O
CH3
O
CH3
CH2Ph
A) NaOCH2CH3, CH3I D) H3O+, then PhCH2Br B) PhCH2MgBr, then H3O+ E) LDA, then PhCH2Br C) CH3MgBr, then PhCH2Br
Ans: E
14. What product results when the following aldol product is treated with dilute acid?
HO H
OPhCH2
Ph
?H3O+
A)
H
OPhCH2
Ph B)
HO CH2 H
OCH2
Ph
Ph
+
C)
H
O
Ph
Ph
D)
O
H
OHPhCH2
Ph
H
E) None of these
Ans: A
Page 12
15. Which of the following sets of reaction conditions will result in the following transformation?
O OH
?
A)
1) PhMgBr / THF 2) H3O+
3) LAH / THF
B) 1) PhMgBr / THF 2) H3O+
3) LDA / THF
C) 1) PhMgBr / THF 2) H3O+
3) LAH / H2O
D) 1) (Ph)2CuLi 2) H3O+
3) NaBH4 / CH3OH
E) 1) (Ph)2CuLi 2) H3O+
3) MCPBA
Ans: D
Page 13
16. Predict the major organic product of the following reaction.
CHO+
O
NaOH / H2OHeat ?
A)
OH O
B)
O
C)
O
D)
OOH
E)
Ans: B
Page 14
17. Predict the major organic product of the following reaction.
O
+
O NaOEt / EtOH
?
A)
O B)
O C)
OOH
D)
O E)
O
Ans: A
Page 15
18. Predict the major organic product of the following reaction sequence.
CH3O
O1) LDA / THF
EtO OEt
O2)
3) LDA / THF 4) CH3CH2OTs 5) Saponification 6) H2O / H+
7) Heat
?
A)
CH3O
O
B)
CH3O
O
C)
CH3O
O
O
O
D)
CH3O
O
O
OEt
E)
CH3O Ans: A
Page 16
19. Predict the major organic product of the following reaction sequence.
O 1) LDA (0.95 eq) / THF
2) CH3OTs 3) MCPBA
?
A)
O
O
B)
O
O
C)
D)
O
E)
O
O
H3C
Ans: B
Page 17
20. The addition of either the methyl Grignard reagent or methyllithium to camphor, followed by hydrolysis, produces a tertiary alcohol known as 2-methylisoborneol, an algal metabolite which imparts a musty odor to water at very low concentrations. However, the yield of alcohol does not exceed 50%, and large amounts of camphor are recovered from the reaction even when a large excess of the Grignard or lithium reagent are used. What would be the most plausible explanation?
Ocamphor
1. CH3MgBr or CH3Li
2. H2OOH
CH3~ 50%
+ ~ 50% unreacted camphor
A) Ketones do not react with Grignard or lithium reagents. B) The Grignard or lithium reagent had obviously degraded during storage. C) The mechanism requires that, for each alcohol formed, one ketone molecule must
remain unreacted. D) With hindered ketones, the organometallic reagent could function as a base rather
than as a nucleophile. E) Alcohol formed early in the reaction could form an unreactive hemiacetal with
remaining ketone. Ans: D
Page 18
21. Predict the product of the following reaction:
O Cl2, H
A)
OCl
B)
HO CH3
C)
Cl OH
D)
Cl
O
E)
Ans: D
Page 19
22. One product of the following reaction would be:
CHO
H
O
KOH/Δ
A)
H
O O
B)
H
OH
C)
H CHO D)
H
O
E) None of these are correct.
Ans: C
23. Which of the following conditions will not successfully alkylate a ketone? A) 1. H2O, H+
2. CH3CH2OH B) 1.
2. CH3CH2Br 3. H+, H2O
C) 1. LDA, THF 2. BrCH2CO2C2H5
D) 1. LDA, THF 2. (CH3)2C=CHCH2Br
E) All of these will alkylate a ketone. Ans: A
Page 20
24. Predict the product of the following reaction:
O1. nBuLi
2. H, H2O
A) HO
B)
OH
C)
O
D)
OH
E)
O
Ans: A
Page 21
25. Predict the product of the following reaction:
O1. (CH3CH2CH2CH2)2CuLi2. CH3CH2I
A)
CH2CH3
(CH2)3CH3
B)
(CH2)3CH3
(CH2)3CH3
O
C)
CH2CH3
(CH2)3CH3
O
D)
CH2CH3
(CH2)3CH3
O
E)
CH2CH3
(CH2)3CH3HO
Ans: D
Page 22
27. Predict the product of the following reaction:
A)
B)
C)
D)
E) both B and C
Ans: E
Page 23
28. Predict the product of the following reaction:
CH3NH2, H2O
O
A)
OHNHCH3
NHCH3 B)
O
OH C)
O
NHCH3 D)
O
NHCH3
NHCH3 E)
Page 24
NCH3
H
Ans: C
29. Given a large excess of D2O, what product(s) would result from the following reaction
at equilibrium?
O
D2O
D+ or -OD?
A)
D
OD
B)
OD
DD
C)
CD3
D3C CD3
O
D DD
D
D
DD
DD
D)
O
DD
D
E) both B and D would be formed Ans: E
Page 25
30. The best reactants to convert cyclohexanone to 2-methylcyclohexanone cleanly would be:
O O
CH3
?
A)
N H
2. CH3I 3. H3O+
1. , H+, - H2O
B)
NaOH, CH3I
C) 1. LDA2. CH3I
D) 1. CH3Li
2. H3O+
E) 1. NaH 2. CH3I
3. H3O+
Ans: A
Page 26
31. What would be the major product of the following reaction?
O
O
?cat. NaOH H2O heat
A)
O
B)
O
C)
O
D)
O
OH E)
O
OH Ans: A
Page 27
32. Which statement is true of the following reactions?
R CHO R CH
OH
OCH3
R CH
OCH3
OCH3reaction IIreaction I
CH3OHCH3OH
A) Reactions I and II are only acid-catalyzed. B) Reaction I is catalyzed by either acid or base, but reaction II requires acid. C) Reactions I and II are both base-catalyzed. D) Reaction II is catalyzed by either acid or base, but reaction I requires acid. E) Both reactions I and II are catalyzed by either acid or base.
Ans: B
