Question 1

Which is the best sequence of reactions for the preparation of p-bromostyrene from ethylbenzene?

Accepted Answer

A)    
B)    
C)    
D)    
E) None of these syntheses is satisfactory. 
A)    
B)    
C)    
D)    
E) None of these syntheses is satisfactory. B

Question 2

What would you expect to be the major product obtained from the following reaction?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) Equal amounts of II and IV. 
A) I 
B) II 
C) III 
D) IV 
E) Equal amounts of II and IV. C

Question 3

Which of the following compounds would be most reactive toward ring bromination?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V C

Question 4

Using a potential energy diagram,explain/illustrate the preferential formation of the 3 substituted product instead of the 2 product in the electrophilic aromatic substitution of benzo[b] thiophene (shown).

Accepted Answer

3-substitution is preferred,since this l

Question 5

Using a potential energy diagram,explain/illustrate the preferential formation of the 2 substituted product instead of the 3 product in the electrophilic aromatic substitution of pyrrole.

Accepted Answer

The 2 substitution product is favored si

Question 6

The major product(s),A,of the following reaction,   would be:

Accepted Answer

A) I 
B) II 
C) A mixture of I and II. 
D) III 
E) IV 
A) I 
B) II 
C) A mixture of I and II. 
D) III 
E) IV

Question 7

Using a potential energy diagram,explain/illustrate the preferential formation of the 1 nitrated product instead of the 2 nitrated product in the electrophilic aromatic nitration of naphthalene.

Accepted Answer

The 1 substitution product is favored si

Question 8

Which of the following structures contribute(s)to the resonance hybrid of the intermediate formed when chlorobenzene undergoes para-chlorination?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) All of these choices. 
A) I 
B) II 
C) III 
D) IV 
E) All of these choices.

Question 9

Which of the following carbocations would be most stable?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 10

What would you expect to be the major product obtained from the following reaction?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) Equal amounts of II and IV. 
A) I 
B) II 
C) III 
D) IV 
E) Equal amounts of II and IV.

Question 11

What might be predicted to happen when the following substance undergoes Friedel-Crafts acylation?

Accepted Answer

A) Substitution occurs in ring B, p- to the methylene group. 
B) Substitution occurs in ring A,o- to the nitro group. 
C) Substitution occurs in ring A,o- to the methylene group. 
D) Substitution occurs in ring B,m- to the methylene group. 
E) None of these choices.No reaction will occur. 
A) Substitution occurs in ring B, p- to the methylene group. 
B) Substitution occurs in ring A,o- to the nitro group. 
C) Substitution occurs in ring A,o- to the methylene group. 
D) Substitution occurs in ring B,m- to the methylene group. 
E) None of these choices.No reaction will occur.

Question 12

Which of the following reactions could be used to synthesize tert-butylbenzene?

Accepted Answer

A)    
B)    
C)    
D) All of these choices. 
E) None of these choices. 
A)    
B)    
C)    
D) All of these choices. 
E) None of these choices.

Question 13

Which of the following reactions would produce cumene?

Accepted Answer

A)    
B)    
C)    
D)    
E) All of these choices. 
A)    
B)    
C)    
D)    
E) All of these choices.

Question 14

A mixture of chlorobenzene (1 mol)and acetanilide (1mol)is allowed to react with Br2 (0.5 mol)in the presence of trace amounts of FeBr3.What is the principal product of the competing reactions?

Accepted Answer

A) 1-bromo-4-chlorobenzene 
B) 1-bromo-2-chlorobenzene 
C) 1-bromo-3-chlorobenzene 
D) 4-bromoacetanilide 
E) 3-bromoacetanilide 
A) 1-bromo-4-chlorobenzene 
B) 1-bromo-2-chlorobenzene 
C) 1-bromo-3-chlorobenzene 
D) 4-bromoacetanilide 
E) 3-bromoacetanilide

Question 15

Which is the best sequence of reactions for the following transformation?

Accepted Answer

A) i)HNO3,H2SO4; ii)CH3MgBr,Et2O; iii)H3O+,heat 
B) i)CH3MgBr,Et2O; ii)H3O+,heat; iii)HNO3,H2SO4 
C) i)HNO3,H2SO4; ii)NaBH4,H2O; iii)H3O+,heat 
D) i)HNO3,H2SO4; ii)LiAlH4,H2O; iii)H3O+,heat 
E) None of these syntheses is satisfactory. 
A) i)HNO3,H2SO4; ii)CH3MgBr,Et2O; iii)H3O+,heat 
B) i)CH3MgBr,Et2O; ii)H3O+,heat; iii)HNO3,H2SO4 
C) i)HNO3,H2SO4; ii)NaBH4,H2O; iii)H3O+,heat 
D) i)HNO3,H2SO4; ii)LiAlH4,H2O; iii)H3O+,heat 
E) None of these syntheses is satisfactory.

Question 16

Which is the best prediction of the site(s)of substitution when 3-methylphenol is nitrated?

Accepted Answer

A) C-2 
B) C-4 
C) C-5 
D) C-6 
E) C-4 and C-6 
A) C-2 
B) C-4 
C) C-5 
D) C-6 
E) C-4 and C-6

Question 17

The major product(s),D,of the following reaction   would be:

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) Equal amounts of I and II. 
A) I 
B) II 
C) III 
D) IV 
E) Equal amounts of I and II.

Question 18

Which of the following reactions would produce isopropylbenzene?

Accepted Answer

A)    
B)    
C)    
D)    
E) All of these choices. 
A)    
B)    
C)    
D)    
E) All of these choices.

Question 19

In general,there are three steps to an electrophilic aromatic substitution reaction.These are:
a)formation of an ___;
b)reaction with an aromatic ring to form an ___; and
c)loss of a ___ to reform the aromatic system.

Accepted Answer

electrophi

Question 20

Based on your knowledge of electrophilic aromatic substitution,predict the preferential position of attack of an electrophile on thiophene,i.e.,does the electrophile E+ attack carbon 2,or 3? Explain your answer.   Which substitution product forms preferentially and why?

Accepted Answer

The 2 substitution product is favored si

Exam 15: Reactions of Aromatic Compounds

Which is the best sequence of reactions for the preparation of p-bromostyrene from ethylbenzene?

What would you expect to be the major product obtained from the following reaction?

Which of the following compounds would be most reactive toward ring bromination?

Using a potential energy diagram,explain/illustrate the preferential formation of the 3 substituted product instead of the 2 product in the electrophilic aromatic substitution of benzo[b] thiophene (shown).

Using a potential energy diagram,explain/illustrate the preferential formation of the 2 substituted product instead of the 3 product in the electrophilic aromatic substitution of pyrrole.

The major product(s),A,of the following reaction, would be:

Using a potential energy diagram,explain/illustrate the preferential formation of the 1 nitrated product instead of the 2 nitrated product in the electrophilic aromatic nitration of naphthalene.

Which of the following structures contribute(s)to the resonance hybrid of the intermediate formed when chlorobenzene undergoes para-chlorination?

Which of the following carbocations would be most stable?

What would you expect to be the major product obtained from the following reaction?

What might be predicted to happen when the following substance undergoes Friedel-Crafts acylation?

Which of the following reactions could be used to synthesize tert-butylbenzene?

Which of the following reactions would produce cumene?

A mixture of chlorobenzene (1 mol)and acetanilide (1mol)is allowed to react with Br2 (0.5 mol)in the presence of trace amounts of FeBr3.What is the principal product of the competing reactions?

Which is the best sequence of reactions for the following transformation?

Which is the best prediction of the site(s)of substitution when 3-methylphenol is nitrated?

The major product(s),D,of the following reaction would be:

Which of the following reactions would produce isopropylbenzene?

In general,there are three steps to an electrophilic aromatic substitution reaction.These are: a)formation of an ___; b)reaction with an aromatic ring to form an ___; and c)loss of a ___ to reform the aromatic system.

Based on your knowledge of electrophilic aromatic substitution,predict the preferential position of attack of an electrophile on thiophene,i.e.,does the electrophile E+ attack carbon 2,or 3? Explain your answer. Which substitution product forms preferentially and why?

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Nucleophilic Reactions

Alkenes and Alkynes I

Alkenes and Alkynes II

Nuclear Magnetic Resonance and Mass Spectrometry

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Filters

A mixture of chlorobenzene (1 mol)and acetanilide (1mol)is allowed to react with Br₂ (0.5 mol)in the presence of trace amounts of FeBr₃.What is the principal product of the competing reactions?

In general,there are three steps to an electrophilic aromatic substitution reaction.These are: a)formation of an _; b)reaction with an aromatic ring to form an _; and c)loss of a ___ to reform the aromatic system.

Based on your knowledge of electrophilic aromatic substitution,predict the preferential position of attack of an electrophile on thiophene,i.e.,does the electrophile E⁺ attack carbon 2,or 3? Explain your answer. Which substitution product forms preferentially and why?