Question 1

Which triene has the largest heat of hydrogenation?

Accepted Answer

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

Question 2

Which triene absorbs the longest wavelength of UV light?

Accepted Answer

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

Question 3

Which of the following is the least reactive diene in a Diels-Alder reaction?

Accepted Answer

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

Question 4

What diene and dienophile are used in a Diels-Alder reaction to prepare the following compound?

Accepted Answer

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

Question 5

Rank the following compounds in order of increasing stability,putting the least stable first.

Accepted Answer

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

Question 6

What is the major product of the following reaction?

Accepted Answer

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

Question 7

Which of the following is a major resonance contributor to the first structure?

Accepted Answer

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

Question 8

Which of the following is an example of a bridged bicyclic system?

Accepted Answer

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

Question 9

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

Accepted Answer

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

Question 10

Which of the following is (are)conjugated dienes?

Accepted Answer

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

Question 11

What is the major product of the following reaction?

Accepted Answer

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

Question 12

Which of the following statements about the Diels-Alder reaction is true?

Accepted Answer

A) The diene can react only when it adopts the s-trans conformation. 
B) Electron-withdrawing substituents in the diene increase reaction rate. 
C) Electron-donating substituents in the dienophile increase the reaction rate. 
D) The stereochemistry of the dienophile is retained in the product. 
A) The diene can react only when it adopts the s-trans conformation. 
B) Electron-withdrawing substituents in the diene increase reaction rate. 
C) Electron-donating substituents in the dienophile increase the reaction rate. 
D) The stereochemistry of the dienophile is retained in the product.

Question 13

Which of the following is not a product obtained from the addition of 1 equivalent of HBr to (E)-1,3-pentadiene?

Accepted Answer

A) (
E) -4-Bromo-2-pentene 
B) (
E) -1-Bromo-2-pentene 
C) 3-Bromo-1-pentene 
D) (
E) -3-Bromo-2-pentene 
A) (
E) -4-Bromo-2-pentene 
B) (
E) -1-Bromo-2-pentene 
C) 3-Bromo-1-pentene 
D) (
E) -3-Bromo-2-pentene

Question 14

Which of the following is not a feature of the Diels-Alder reaction?

Accepted Answer

A) They are initiated by peroxides. 
B) They form new six-membered rings. 
C) Three π bonds break. 
D) They are concerted. 
A) They are initiated by peroxides. 
B) They form new six-membered rings. 
C) Three π bonds break. 
D) They are concerted.

Question 15

Which of the following is the appropriate term for the mechanism of the addition of HBr to 1,3-dienes?

Accepted Answer

A) Nucleophilic addition 
B) Electrophilic addition 
C) Free radical addition 
D) Conjugate addition 
A) Nucleophilic addition 
B) Electrophilic addition 
C) Free radical addition 
D) Conjugate addition

Question 16

Which of the following electronic transitions is common in the UV spectrum of 1,3-butadiene?

Accepted Answer

A) s®p 
B) s®p* 
C) n ®p* 
D) p®p* 
A) s®p 
B) s®p* 
C) n ®p* 
D) p®p*

Question 17

Which of the following is the most reactive diene in a Diels-Alder reaction?

Accepted Answer

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

Question 18

What is the major organic product of the following reaction?

Accepted Answer

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

Question 19

Rank the following dienophile in order of increasing reactivity in a Diels-Alder reaction,listing the least reactive first.

Accepted Answer

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

Question 20

What is the kinetic product obtained from the addition of 1 equivalent of HBr to 1,3-butadiene?

Accepted Answer

A) 3-Bromo-1-butene 
B) 1-Bromo-2-butene 
C) 2-Bromo-2-butene 
D) 2-Bromo-1-butene 
A) 3-Bromo-1-butene 
B) 1-Bromo-2-butene 
C) 2-Bromo-2-butene 
D) 2-Bromo-1-butene

Exam 14: Conjugation, resonance, and Dienes

Which triene has the largest heat of hydrogenation?

Which triene absorbs the longest wavelength of UV light?

Which of the following is the least reactive diene in a Diels-Alder reaction?

What diene and dienophile are used in a Diels-Alder reaction to prepare the following compound?

Rank the following compounds in order of increasing stability,putting the least stable first.

What is the major product of the following reaction?

Which of the following is a major resonance contributor to the first structure?

Which of the following is an example of a bridged bicyclic system?

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

Which of the following is (are)conjugated dienes?

What is the major product of the following reaction?

Which of the following statements about the Diels-Alder reaction is true?

Which of the following is not a product obtained from the addition of 1 equivalent of HBr to (E)-1,3-pentadiene?

Which of the following is not a feature of the Diels-Alder reaction?

Which of the following is the appropriate term for the mechanism of the addition of HBr to 1,3-dienes?

Which of the following electronic transitions is common in the UV spectrum of 1,3-butadiene?

Which of the following is the most reactive diene in a Diels-Alder reaction?

What is the major organic product of the following reaction?

Rank the following dienophile in order of increasing reactivity in a Diels-Alder reaction,listing the least reactive first.

What is the kinetic product obtained from the addition of 1 equivalent of HBr to 1,3-butadiene?

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 and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives - Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Molecular Ion Peaks and Fragmentation Patterns

Analyzing Molecular Motion and Infrared Spectroscopy

Organic Spectroscopy Concepts

Filters