Question 1

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 
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 2

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

Accepted Answer

@#IMG-DLM&_TB1830_00

Question 3

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 
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 4

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

Question 5

Give the product for the following reaction.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 6

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

Question 7

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 
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 8

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

Question 9

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. 
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 10

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 
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 11

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 
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 12

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

Question 13

What does LCAO stand for?

Accepted Answer

Linear com

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

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 16

Give the product(s)for the following reaction.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 17

Give the product(s)for the following reaction.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 18

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

Accepted Answer

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

Question 19

(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 20

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

Accepted Answer

The molecular orbital is an ou

Exam 28: Pericyclic Reactions

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

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

Which of the following statements best describes the term suprafacial?

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

Give the product for the following reaction.

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

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

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

Describe a sigmatropic rearrangement.

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

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

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

What does LCAO stand for?

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

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

Give the product(s)for the following reaction.

Give the product(s)for the following reaction.

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

(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

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

Remembering General Chemistry: Electronic Structure and Bonding

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An Introduction to Organic Compounds

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