Question 1

Consider the structures given below.Which of them would be a relatively stable contributor to the hybrid formed when toluene undergoes para bromination?

Accepted Answer

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

Question 2

Which reagent would you use to carry out the following transformation? tert-butylbenzene $\to$ p-tert-butylbenzenesulfonic acid
+
O-tert-butylbenzenesulfonic acid

Accepted Answer

A) HNO3/H2SO4 
B) tert-C4H9Cl/AlCl3 
C) H2SO3/peroxides 
D) SO3/H2SO4 
E) SO2/H2SO3 
A) HNO3/H2SO4 
B) tert-C4H9Cl/AlCl3 
C) H2SO3/peroxides 
D) SO3/H2SO4 
E) SO2/H2SO3

Question 3

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

Accepted Answer

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

Question 4

Which of these is the rate-determining step in the bromination of benzene?

Accepted Answer

A) Complexation of bromine with the iron(III)bromide catalyst 
B) Formation of Br+ ion 
C) Addition of Br+ to benzene to form the arenium ion 
D) Loss of a proton from the arenium ion to form bromobenzene 
E) None of these choices. 
A) Complexation of bromine with the iron(III)bromide catalyst 
B) Formation of Br+ ion 
C) Addition of Br+ to benzene to form the arenium ion 
D) Loss of a proton from the arenium ion to form bromobenzene 
E) None of these choices.

Question 5

How might the following synthesis be carried out:

Accepted Answer

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

Question 6

The major product(s)of the following reaction,

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

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

Question 8

Based on your knowledge of electrophilic aromatic substitution,predict the preferential position of nitration of naphthalene,i.e.,does the NO2+ attack carbon 1,or 2? Explain your answer.   Which substitution product forms preferentially and why?

Accepted Answer

The 1 substitution product is favored si

Question 9

The major product(s)of the following reaction,

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 10

Which would be the product of the following reaction sequence?

Accepted Answer

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

Question 11

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] furane (shown).

Accepted Answer

3-substitution is preferred,since this l

Question 12

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

Question 13

The ortho/para product ratio is expected to be the smallest for the bromination of which of these?

Accepted Answer

A) Toluene 
B) Isopropylbenzene 
C) Butylbenzene 
D) sec-Butylbenzene 
E) tert-Butylbenzene 
A) Toluene 
B) Isopropylbenzene 
C) Butylbenzene 
D) sec-Butylbenzene 
E) tert-Butylbenzene

Question 14

Which of the following is not a meta-directing substituent when present on the benzene ring?

Accepted Answer

A) -NHCOCH3 
B) -NO2 
C) -N(CH3)3+ 
D) -C$\equiv$N 
E) -CO2H 
A) -NHCOCH3 
B) -NO2 
C) -N(CH3)3+ 
D) -C$\equiv$N 
E) -CO2H

Question 15

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

Accepted Answer

A) i)HNO3,H2SO4; ii)CH3MgBr,Et2O; iii)H2O,NH4Cl 
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)H2O,NH4Cl 
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

What would you expect to be the major product obtained from the monobromination of m-dichlorobenzene?

Accepted Answer

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

Question 17

How might the following synthesis be carried out:

Accepted Answer

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

Question 18

How might the following synthesis be carried out:

Accepted Answer

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

Question 19

The compound 4-bromo-1-propylbenzene is best made from benzene by the application of these reagents in the order shown:

Accepted Answer

A) (1)Br2,Fe (2)CH3CH2CH2Cl,AlCl3 
B) (1)CH3CH2CH2Cl,AlCl3 (2)Br2,Fe 
C)    
D)    
E) (1)(CH3)2CHCl,AlCl3 (2)Br2,Fe 
A) (1)Br2,Fe (2)CH3CH2CH2Cl,AlCl3 
B) (1)CH3CH2CH2Cl,AlCl3 (2)Br2,Fe 
C)    
D)    
E) (1)(CH3)2CHCl,AlCl3 (2)Br2,Fe

Question 20

Each of the five disubstituted benzenes shown below is nitrated.In which of these cases does the arrow not indicate the chief position of nitration.

Accepted Answer

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

Exam 15: Reactions of Aromatic Compounds

Consider the structures given below.Which of them would be a relatively stable contributor to the hybrid formed when toluene undergoes para bromination?

Which reagent would you use to carry out the following transformation? tert-butylbenzene →\to→ p-tert-butylbenzenesulfonic acid + O-tert-butylbenzenesulfonic acid

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

Which of these is the rate-determining step in the bromination of benzene?

How might the following synthesis be carried out:

The major product(s)of the following reaction,

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

Based on your knowledge of electrophilic aromatic substitution,predict the preferential position of nitration of naphthalene,i.e.,does the NO2+ attack carbon 1,or 2? Explain your answer. Which substitution product forms preferentially and why?

The major product(s)of the following reaction,

Which would be the product of the following reaction sequence?

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] furane (shown).

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

The ortho/para product ratio is expected to be the smallest for the bromination of which of these?

Which of the following is not a meta-directing substituent when present on the benzene ring?

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

What would you expect to be the major product obtained from the monobromination of m-dichlorobenzene?

How might the following synthesis be carried out:

How might the following synthesis be carried out:

The compound 4-bromo-1-propylbenzene is best made from benzene by the application of these reagents in the order shown:

Each of the five disubstituted benzenes shown below is nitrated.In which of these cases does the arrow not indicate the chief position of nitration.

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

Which reagent would you use to carry out the following transformation? tert-butylbenzene $\to$ p-tert-butylbenzenesulfonic acid + O-tert-butylbenzenesulfonic acid

Based on your knowledge of electrophilic aromatic substitution,predict the preferential position of nitration of naphthalene,i.e.,does the NO₂⁺ attack carbon 1,or 2? Explain your answer. Which substitution product forms preferentially and why?