Question 1

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) None of the above
F) A) and B)

Question 2

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

Accepted Answer

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

Question 3

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

Accepted Answer

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

Question 4

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

Accepted Answer

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

Question 5

Which of the following compound absorbs UV light at the longest wavelength?

Accepted Answer

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

Question 6

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

Accepted Answer

A)  sp
B)  sp*
C)  n p*
D)  pp*E) A) and D)
F) A) and C)

Question 7

Which triene absorbs the longest wavelength of UV light?

Accepted Answer

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

Question 8

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-buteneE) None of the above
F) A) and B)

Question 9

Which of the following compound absorbs UV light at the longest wavelength?

Accepted Answer

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

Question 10

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) None of the above

Question 11

What is the reactive intermediate in the reaction of 1,3-diene with HBr, resulting in 1,4-addition?

Accepted Answer

A)  Allylic radical
B)  Cyclic bromonium
C)  Dienophile
D)  Allylic carbocationE) None of the above
F) A) and B)

Question 12

Which of the following statements about kinetic vs.thermodynamic products is true?

Accepted Answer

A)  The product that is formed faster is the thermodynamic product.
B)  The kinetic product predominates at low temperature.
C)  The product that predominates at equilibrium is the kinetic product.
D)  The thermodynamic product is less stable.E) A) and B)
F) All of the above

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-penteneE) All of the above
F) None of the above

Question 14

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 IIIE) B) and C)
F) All of the above

Question 15

What is the hybridization around the indicated carbon 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 D)
F) None of the above

Question 16

Which of the following is not a resonance structure of acetic anhydride?

Accepted Answer

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

Question 17

Which of the following statements about resonance structures is true?

Accepted Answer

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

Question 18

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 C)
F) A) and D)

Question 19

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) All of the above
F) A) and C)

Question 20

What is the major organic product of the following reaction?

Accepted Answer

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

Exam 16: Conjugation, Resonance, and Dienes

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

What is the major organic product of the following reaction?

Correct AnswerverifiedShow Answer

Which of the following statements about resonance structures is true?

Correct AnswerverifiedShow Answer

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

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

Correct AnswerverifiedShow Answer

Which of the following is not a resonance structure of acetic anhydride?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following compound absorbs UV light at the longest wavelength?

Correct AnswerverifiedShow Answer

What is the reactive intermediate in the reaction of 1,3-diene with HBr, resulting in 1,4-addition?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following compound absorbs UV light at the longest wavelength?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following statements about kinetic vs.thermodynamic products is true?

Correct AnswerverifiedShow Answer

What is the major organic product of the following reaction?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which triene absorbs the longest wavelength of UV light?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified