Organic Chemistry, 5e (Klein)
Chapter 21 Alpha Carbon Chemistry: Enols and Enolates
1) Which one of the compounds shown is most acidic?
A) ethyl acetoacetate
B) 2-butanone
C) ethyl pentanoate
D) 1-butanol
E) 3-pentanone
Answer: A
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
2) How many alpha hydrogens are in 2-pentanone?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: E
Diff: Easy
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
3) How many beta hydrogens are in 2-pentanone?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: B
Diff: Easy
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
4) How many gamma hydrogens are in 2-pentanone?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: C
Diff: Easy
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
1
,5) Which of the indicated α-hydrogens is most acidic?
A) I
B) II
C) III
D) IV
E) V
Answer: B
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
6) Which is the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: A
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
2
,7) Which is the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: E
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
8) Which is the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: C
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
3
, 9) Which carbon atom has the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: C
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
4
Chapter 21 Alpha Carbon Chemistry: Enols and Enolates
1) Which one of the compounds shown is most acidic?
A) ethyl acetoacetate
B) 2-butanone
C) ethyl pentanoate
D) 1-butanol
E) 3-pentanone
Answer: A
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
2) How many alpha hydrogens are in 2-pentanone?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: E
Diff: Easy
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
3) How many beta hydrogens are in 2-pentanone?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: B
Diff: Easy
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
4) How many gamma hydrogens are in 2-pentanone?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: C
Diff: Easy
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
1
,5) Which of the indicated α-hydrogens is most acidic?
A) I
B) II
C) III
D) IV
E) V
Answer: B
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
6) Which is the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: A
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
2
,7) Which is the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: E
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
8) Which is the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: C
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
3
, 9) Which carbon atom has the most acidic hydrogen in the compound shown?
A) I
B) II
C) III
D) IV
E) V
Answer: C
Diff: Medium
Learning Objective: 21.1 Draw the mechanism for the acid- or base-catalyzed tautomerization
of an aldehyde or ketone and describe the conditions required for enolate formation.
4
