Question 1

Indicate whether each of the following reactions is an electrocyclic reaction, a cycloaddition reaction, or a sigmatropic rearrangement.

Accepted Answer

a) Is an electrocycl...

Question 2

Under what conditions would a 1,5-hydrogen shift occur in a sigmatropic rearrangement?

Accepted Answer

A)  thermal conditions
B)  photochemical conditions
C)  suprafacial pathway
D)  A and C
E)  B and C

Question 3

What are the structures of A, B, and C?

Accepted Answer

<img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30">_TB1830_00...

Question 4

Give the product(s) for the following reaction.

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 5

Which of the following molecular orbitals is produced when in-phase atomic orbitals overlap?

Accepted Answer

A)  a bonding molecular orbital
B)  an antibonding molecular orbital
C)  a nonbonding molecular orbital
D)  an out-of-phase molecular orbital
E)  an excited energy state of molecular orbital

Question 6

Give the product(s) for the following reaction.

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 7

Describe a sigmatropic rearrangement.

Accepted Answer

A)  A sigma bond in the reactant has moved to a different location in the product, and the pi bonds have rearranged.
B)  The product contains a new ring, with two less sigma bonds, and two more pi bonds than the starting material.
C)  The product contains a new ring, with two more sigma bonds, and two less pi bonds than the starting material.
D)  The product contains a new ring, with one less sigma bond, and one more pi bond than the starting material.
E)  The product contains a new ring, with one more sigma bond, and one less pi bond than the starting material.

Question 8

Which of the following reactions best describes the Diels-Alder reaction?

Accepted Answer

A)  electrocyclic reaction
B)  cycloaddition reaction
C)  sigmatropic reaction
D)  radical reaction
E)  nucleophilic substitution reaction

Question 9

Which of the following statements best describes the term suprafacial?

Accepted Answer

A)  formation of two sigma bonds from the same side of the pi system
B)  formation of two pi bonds from the same side of the sigma system
C)  formation of two sigma bonds from opposite sides of the pi system
D)  formation of two pi bonds from opposite sides of the sigma system
E)  an anti cycloaddition

Question 10

What does LCAO stand for?

Accepted Answer

Linear com...

Question 11

Under photochemical conditions, (2E,4Z) -hexadiene undergoes a ________ ring closure to yield ________.

Accepted Answer

A)  conrotatory, cis-3,4-dimethylcyclobutene
B)  conrotatory, trans-3,4-dimethylcyclobutene
C)  disrotatory, cis-3,4-dimethylcyclobutene
D)  disrotatory, trans-3,4-dimethylcyclobutene

Question 12

How many nodes does the highest energy molecular orbital of 1,3,5,7-octatetraene have?

Accepted Answer

A)  4
B)  5
C)  6
D)  8
E)  10

Question 13

(a) Under thermal conditions, will ring closure of (2E,4Z,6Z,8E)-decatetraene be conrotatory or disrotatory? Explain.
(b) Will the product be cis or trans? Explain

Accepted Answer

(a) Since the number of conjugated pi bo...

Question 14

Provide the major organic product of the following Diels-Alder cycloaddition.

Accepted Answer

The answer of Provide the major organic product of the...

Question 15

Through what type of single pericyclic reaction did the reaction shown below proceed?

Accepted Answer

A)  [1,2] sigmatropic hydrogen migration
B)  [1,3] sigmatropic hydrogen migration
C)  [1,4] sigmatropic hydrogen migration
D)  [1,5] sigmatropic hydrogen migration
E)  none of the above

Question 16

What is the product from the following 1,3-carbon shift reaction?

Accepted Answer

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

Question 17

Which of the following best describes the sigmatropic rearrangement that occurs in the reaction shown below?

Accepted Answer

A)  [1,3] sigmatropic rearrangement
B)  [2,3] sigmatropic rearrangement
C)  [3,3] sigmatropic rearrangement
D)  [1,5] sigmatropic rearrangement
E)  [1,4] sigmatropic rearrangement

Question 18

Give the product for the following reaction.

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 19

How many nodes would you expect from the following atomic orbital overlap?

Accepted Answer

The molecular orbital is an ou...

Question 20

Which molecular orbital is higher in energy: the in-phase or out-of-phase overlap of atomic orbitals?

Accepted Answer

Out-of-phase overlap of atomic...

Exam 28: Pericyclic Reactions

Under photochemical conditions, (2E,4Z) -hexadiene undergoes a ________ ring closure to yield ________.

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How many nodes does the highest energy molecular orbital of 1,3,5,7-octatetraene have?

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Which of the following best describes the sigmatropic rearrangement that occurs in the reaction shown below?

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Which of the following reactions best describes the Diels-Alder reaction?

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What does LCAO stand for?

Correct AnswerverifiedLinear com...View AnswerShow Answer

What are the structures of A, B, and C?

Correct Answerverified_TB1830_00...View AnswerShow Answer

Under what conditions would a 1,5-hydrogen shift occur in a sigmatropic rearrangement?

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Describe a sigmatropic rearrangement.

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(a) Under thermal conditions, will ring closure of (2E,4Z,6Z,8E)-decatetraene be conrotatory or disrotatory? Explain. (b) Will the product be cis or trans? Explain

Correct Answerverified(a) Since the number of conjugated pi bo...View AnswerShow Answer

Which of the following statements best describes the term suprafacial?

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Through what type of single pericyclic reaction did the reaction shown below proceed?

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How many nodes would you expect from the following atomic orbital overlap?

Correct AnswerverifiedThe molecular orbital is an ou...View AnswerShow Answer

What is the product from the following 1,3-carbon shift reaction?

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Which of the following molecular orbitals is produced when in-phase atomic orbitals overlap?

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Give the product(s) for the following reaction.

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Give the product(s) for the following reaction.

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Indicate whether each of the following reactions is an electrocyclic reaction, a cycloaddition reaction, or a sigmatropic rearrangement.

Correct Answerverifieda) Is an electrocycl...View AnswerShow Answer

Give the product for the following reaction.

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Which molecular orbital is higher in energy: the in-phase or out-of-phase overlap of atomic orbitals?

Correct AnswerverifiedOut-of-phase overlap of atomic...View AnswerShow Answer

Provide the major organic product of the following Diels-Alder cycloaddition.

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Under photochemical conditions, (2E,4Z) -hexadiene undergoes a ring closure to yield .

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Linear com...
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_TB1830_00...
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(a) Since the number of conjugated pi bo...
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The molecular orbital is an ou...
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a) Is an electrocycl...
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Out-of-phase overlap of atomic...
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