Question 1

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

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) B) and D)
F) All of the above

Question 2

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.E) B) and C)
F) All of the above

Question 3

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

Accepted Answer

A)   Only I
B)   Only I and III
C)   Only II and IV
D)   Only I, II, and IIIE) A) and D)
F) B) and D)

Question 4

What is the thermodynamic 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-buteneE) A) and B)
F) C) and D)

Question 5

Which of the following compounds is conjugated?

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) B) and D)
F) A) and C)

Question 6

What is the major organic product of the following reaction?

Accepted Answer

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

Question 7

Rank the following dienes in order of decreasing heat of hydrogenation, putting the diene with the highest heat of hydrogenation first.  II > III B)  III > II > I C)  II > I > III D)  III > I > II" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I > II > III
B)   III > II > I
C)   II > I > III
D)   III > I > IIE) B) and D)
F) C) and D)

Question 8

What is the hybridization around the indicated oxygen atom in the following anion? 3 B)  sp2 C)  sp D)  p" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   sp3
B)   sp2
C)   sp
D)   pE) B) and C)
F) A) and D) B

Question 9

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

Accepted Answer

A)   I 
B)   III 
C)   II 
D)   III < II < IE) C) and D)
F) None of the above

Question 10

Which of the following dienes contain isolated double bonds?

Accepted Answer

A)   Only I and II
B)   Only II and III
C)   Only I and III
D)   Only II and IVE) All of the above
F) C) and D) D

Question 11

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 IIIE) B) and D)
F) None of the above B

Question 12

Which of the following conjugated dienes represent two conformations?

Accepted Answer

A)   Only I and II
B)   Only I and III
C)   Only II and III
D)   None of the choicesE) All of the above
F) B) and C)

Question 13

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

Accepted Answer

A)   I 
B)   III 
C)   II 
D)   III < I < IIE) A) and D)
F) C) and D)

Question 14

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

Accepted Answer

A)   Three pi bonds break; two sigma bonds and one pi bond form.
B)   Three pi bonds break; one sigma bond and two pi bonds form.
C)   Two pi bonds break; one sigma bond and one pi bond form.
D)   Two pi bonds break; two sigma bonds and one pi bond form.E) A) and D)
F) B) and D)

Question 15

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

Accepted Answer

A)   I 
B)   III 
C)   II 
D)   I < III < IIE) None of the above
F) A) and C)

Question 16

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

Accepted Answer

A)   Only I
B)   Only II and IV
C)   Only I and III
D)   Only I, II and IIIE) A) and B)
F) A) and C)

Question 17

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

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) A) and C)
F) A) and B)

Question 18

Which of the following statements about resonance structures is true?

Accepted Answer

A)   The placement of atoms is different.
B)   The placement of  bonds is different.
C)   The placement of  bonds is different.
D)   The placement of nonbonded electrons is the same.E) B) and D)
F) B) and C)

Question 19

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

Accepted Answer

A)   "  "
B)   "  *"
C)   "n  *"
D)   "  *"E) All of the above
F) None of the above

Question 20

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

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) A) and D)
F) A) and B)

Exam 16: Conjugation, Resonance, and Dienes

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following compounds is conjugated?

Correct AnswerverifiedShow Answer

What is the major organic product of the following reaction?

Correct AnswerverifiedShow Answer

Rank the following dienes in order of decreasing heat of hydrogenation, putting the diene with the highest heat of hydrogenation first.

Correct AnswerverifiedShow Answer

What is the hybridization around the indicated oxygen atom in the following anion?

Correct AnswerverifiedB

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

Correct AnswerverifiedShow Answer

Which of the following dienes contain isolated double bonds?

Correct AnswerverifiedD

Which of the following is (are) conjugated dienes?

Correct AnswerverifiedB

Which of the following conjugated dienes represent two conformations?

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following statements about resonance structures is true?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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B

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D

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B

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