Question 1

What is the major product of electrophilic addition of HBr to the following alkene?

Accepted Answer

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

Question 2

What are the product(s) of the following reaction?

Accepted Answer

A) Only I 
B) Only II 
C) Only I and II 
D) Only III 
A) Only I 
B) Only II 
C) Only I and II 
D) Only III

Question 3

What is the structure of compound A?

Accepted Answer

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

Question 4

Rank the following activating groups in order of decreasing strength of activation, listing the most activating first.

Accepted Answer

A) IV > II > III > I 
B) II > III > IV > I 
C) III > IV > II > I 
D) II > IV > III > I 
A) IV > II > III > I 
B) II > III > IV > I 
C) III > IV > II > I 
D) II > IV > III > I

Question 5

Which of the following statements about the mechanism of electrophilic aromatic substitution is not true?

Accepted Answer

A) All electrophilic aromatic substitution reactions occur via a two-step mechanism. 
B) The transition state of the first step is lower in energy. 
C) The first step is the rate-determining step. 
D) The second step is the fast step. 
A) All electrophilic aromatic substitution reactions occur via a two-step mechanism. 
B) The transition state of the first step is lower in energy. 
C) The first step is the rate-determining step. 
D) The second step is the fast step.

Question 6

What is the reactive intermediate formed in the addition-elimination mechanism of nucleophilic aromatic substitution?

Accepted Answer

A) Carbocation 
B) Radical 
C) Benzyne 
D) Carbanion 
A) Carbocation 
B) Radical 
C) Benzyne 
D) Carbanion

Question 7

What is the product of the following sequence of reactions?

Accepted Answer

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

Question 8

What is the driving force for losing a proton as the last step in electrophilic aromatic substitution?

Accepted Answer

A) To neutralize the base that is present 
B) To make room for the electrophile 
C) To make the ring more reactive 
D) To rearomatize the ring system 
A) To neutralize the base that is present 
B) To make room for the electrophile 
C) To make the ring more reactive 
D) To rearomatize the ring system

Question 9

What is the major organic product obtained from the following reaction?

Accepted Answer

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

Question 10

Which of the following statements about nucleophilic aromatic substitution is not true?

Accepted Answer

A) Increasing the electronegativity of the halogen increases the reactivity of the aryl halide. 
B) Increasing the number of electron-withdrawing groups increases the reactivity of the aryl halide. 
C) Electron-withdrawing groups stabilize the intermediate carbanion, and lower the energy of the transition state. 
D) When a nitro group is located meta to the halogen, the negative charge of the intermediate carbanion can be delocalized onto the NO2 group, thus stabilizing it. 
A) Increasing the electronegativity of the halogen increases the reactivity of the aryl halide. 
B) Increasing the number of electron-withdrawing groups increases the reactivity of the aryl halide. 
C) Electron-withdrawing groups stabilize the intermediate carbanion, and lower the energy of the transition state. 
D) When a nitro group is located meta to the halogen, the negative charge of the intermediate carbanion can be delocalized onto the NO2 group, thus stabilizing it.

Question 11

Which set of reagents would most likely bring about the following transformation?

Accepted Answer

A) Br2 and FeBr3 
B) NBS and light 
C) Br2 in CCl4 
D) NaBr and H2O 
A) Br2 and FeBr3 
B) NBS and light 
C) Br2 in CCl4 
D) NaBr and H2O

Question 12

What is the major organic product obtained from the following reaction?

Accepted Answer

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

Question 13

Which of the following halides will not work as an electrophile in a Friedel-Crafts alkylation reaction?

Accepted Answer

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

Question 14

How can polyalkylation be minimized in Friedel-Crafts alkylation?

Accepted Answer

A) Use a large excess of alkyl halide relative to the aromatic compound. 
B) Use a large excess of benzene relative to the alkyl halide. 
C) Use an alkyl halide without a Lewis acid catalyst. 
D) Use a large excess of the Lewis acid catalyst. 
A) Use a large excess of alkyl halide relative to the aromatic compound. 
B) Use a large excess of benzene relative to the alkyl halide. 
C) Use an alkyl halide without a Lewis acid catalyst. 
D) Use a large excess of the Lewis acid catalyst.

Question 15

In addition to the product shown, what other product is formed in the following reaction?

Accepted Answer

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

Question 16

What are the two distinct pathways for nucleophilic aromatic substitution?

Accepted Answer

A) Addition-substitution and substitution-addition 
B) Addition-elimination and elimination-addition 
C) Addition-addition and elimination-elimination 
D) Elimination-substitution and substitution-elimination 
A) Addition-substitution and substitution-addition 
B) Addition-elimination and elimination-addition 
C) Addition-addition and elimination-elimination 
D) Elimination-substitution and substitution-elimination

Question 17

Consider the tetracyclic aromatic compound drawn below, with rings labelled as I, II, III, and IV.Which of the four rings is least reactive in electrophilic aromatic substitution?

Accepted Answer

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

Question 18

What are the product(s) of the following reaction?

Accepted Answer

A) Only I and II 
B) Only I and III 
C) Only II and III 
D) Only IV 
A) Only I and II 
B) Only I and III 
C) Only II and III 
D) Only IV

Question 19

What is the product of the following reaction?

Accepted Answer

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

Question 20

What is a major problem with Friedel-Crafts alkylation?

Accepted Answer

A) It requires high temperatures. 
B) The conditions are too acidic. 
C) The starting material is frequently over-alkylated. 
D) The products coordinate with the aluminum chloride. 
A) It requires high temperatures. 
B) The conditions are too acidic. 
C) The starting material is frequently over-alkylated. 
D) The products coordinate with the aluminum chloride.

Exam 18: Reactions of Aromatic Compounds

What is the major product of electrophilic addition of HBr to the following alkene?

What are the product(s) of the following reaction?

What is the structure of compound A?

Rank the following activating groups in order of decreasing strength of activation, listing the most activating first.

Which of the following statements about the mechanism of electrophilic aromatic substitution is not true?

What is the reactive intermediate formed in the addition-elimination mechanism of nucleophilic aromatic substitution?

What is the product of the following sequence of reactions?

What is the driving force for losing a proton as the last step in electrophilic aromatic substitution?

What is the major organic product obtained from the following reaction?

Which of the following statements about nucleophilic aromatic substitution is not true?

Which set of reagents would most likely bring about the following transformation?

What is the major organic product obtained from the following reaction?

Which of the following halides will not work as an electrophile in a Friedel-Crafts alkylation reaction?

How can polyalkylation be minimized in Friedel-Crafts alkylation?

In addition to the product shown, what other product is formed in the following reaction?

What are the two distinct pathways for nucleophilic aromatic substitution?

Consider the tetracyclic aromatic compound drawn below, with rings labelled as I, II, III, and IV.Which of the four rings is least reactive in electrophilic aromatic substitution?

What are the product(s) of the following reaction?

What is the product of the following reaction?

What is a major problem with Friedel-Crafts alkylation?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers, and Related Compounds

Alkenes

Alkynes

Oxidation and Reduction

Mass Spectrometry and Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Radical Reactions

Conjugation, Resonance, and Dienes

Benzene and Aromatic Compounds

Carboxylic Acids and the Acidity of the O-H Bond

Introduction to Carbonyl Chemistry;

Aldehydes and Ketones Nucleophilic Addition

Carboxylic Acids and Derivatives

Substitution Reactions of Carbonyl Compounds at the Alpha-Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Filters