Question 1

Give the conditions for 1,5-hydrogen shifts.

Accepted Answer

A) suprafacial rearrangement 
B) antarafacial rearrangement 
C) thermal conditions 
D) photochemical conditions 
E) all of the above 
A) suprafacial rearrangement 
B) antarafacial rearrangement 
C) thermal conditions 
D) photochemical conditions 
E) all of the above

Question 2

Under thermal conditions, is an [8+2] cycloaddition suprafacial or antarafacial?

Accepted Answer

The answer of Under thermal conditions, is an [8+2] cycloaddition...

Question 3

When an allyl cation undergoes a cycloaddition under photochemical conditions with ethylene (bonds forming at the ends of the π-systems), the cycloaddition is described as ________.

Accepted Answer

A) [2+2] and suprafacial 
B) [2+4] and suprafacial 
C) [2+2] and antarafacial 
D) [2+4] and antarafacial 
E) [2+3] and antarafacial 
A) [2+2] and suprafacial 
B) [2+4] and suprafacial 
C) [2+2] and antarafacial 
D) [2+4] and antarafacial 
E) [2+3] and antarafacial

Question 4

Give the product for the following reaction.

Accepted Answer

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

Question 5

What type of pericyclic process is occurring in the reaction below? Provide two reasons why the equilibrium lies in the direction indicated.

Accepted Answer

A [3,3] sigmatropic rearrangement is occ

Question 6

Under thermal conditions, (2E,4E)-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 7

What diene and dienophile would react to give the product below?

Accepted Answer

The answer of What diene and dienophile would react to...

Question 8

Provide the structure of the major organic product in the following reaction.

Accepted Answer

@#IMG-DLM&_TB1830_00

Question 9

What is the major product of the following reaction?

Accepted Answer

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

Question 10

What characterizes a pericyclic reaction?

Accepted Answer

Pericyclic reactions involve c

Question 11

Under photochemical conditions, is an [2+2] cycloaddition suprafacial or antarafacial?

Accepted Answer

The answer of Under photochemical conditions, is an [2+2] cycloaddition...

Question 12

Give a representation of the antibonding π molecular orbital of the allyl anion.

Accepted Answer

The answer of Give a representation of the antibonding π...

Question 13

Describe a Claisen rearrangement.

Accepted Answer

A) [3,3] sigmatropic rearrangement of a 1,5-diene 
B) [1,3] sigmatropic rearrangement of an alkene 
C) [3,3] sigmatropic rearrangement of an allyl vinyl ether 
D) [1,5] sigmatropic rearrangement of a 1,3-diene 
E) [2,3] sigmatropic rearrangement of an alkene 
A) [3,3] sigmatropic rearrangement of a 1,5-diene 
B) [1,3] sigmatropic rearrangement of an alkene 
C) [3,3] sigmatropic rearrangement of an allyl vinyl ether 
D) [1,5] sigmatropic rearrangement of a 1,3-diene 
E) [2,3] sigmatropic rearrangement of an alkene

Question 14

What is/are the product(s)of the following 1,3-hydrogen shift?

Accepted Answer

A) I 
B) II 
C) III 
D) I and II 
E) I and III 
A) I 
B) II 
C) III 
D) I and II 
E) I and III

Question 15

Why does the diene shown below fail to undergo a Diels-Alder reaction with even the most reactive dienophiles?

Accepted Answer

The diene cannot ach

Question 16

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

Accepted Answer

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

Question 17

Give a representation of the bonding π molecular orbital of the allyl cation.

Accepted Answer

The answer of Give a representation of the bonding π...

Question 18

In the allyl radical, which π molecular orbital is singly occupied?

Accepted Answer

A) the bonding π molecular orbital 
B) the nonbonding π molecular orbital 
C) the antibonding π molecular orbital 
D) none of the above 
A) the bonding π molecular orbital 
B) the nonbonding π molecular orbital 
C) the antibonding π molecular orbital 
D) none of the above

Question 19

What is the major product of the following reaction?

Accepted Answer

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

Question 20

Give the product for the following [1,5] sigmatropic rearrangement.

Accepted Answer

The answer of Give the product for the following [1,5]...

Exam 28: Pericyclic Reactions

Give the conditions for 1,5-hydrogen shifts.

Under thermal conditions, is an [8+2] cycloaddition suprafacial or antarafacial?

When an allyl cation undergoes a cycloaddition under photochemical conditions with ethylene (bonds forming at the ends of the π-systems), the cycloaddition is described as ________.

Give the product for the following reaction.

What type of pericyclic process is occurring in the reaction below? Provide two reasons why the equilibrium lies in the direction indicated.

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

What diene and dienophile would react to give the product below?

Provide the structure of the major organic product in the following reaction.

What is the major product of the following reaction?

What characterizes a pericyclic reaction?

Under photochemical conditions, is an [2+2] cycloaddition suprafacial or antarafacial?

Give a representation of the antibonding π molecular orbital of the allyl anion.

Describe a Claisen rearrangement.

What is/are the product(s)of the following 1,3-hydrogen shift?

Why does the diene shown below fail to undergo a Diels-Alder reaction with even the most reactive dienophiles?

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

Give a representation of the bonding π molecular orbital of the allyl cation.

In the allyl radical, which π molecular orbital is singly occupied?

What is the major product of the following reaction?

Give the product for the following [1,5] sigmatropic rearrangement.

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds

Isomers: the Arrangement of Atoms in Space

Alkenes Thermodynamics and Kinetics

Reactions of Alkenes

Reactions of Alkynes Introduction to Multistep Synthesis

Electron Delocalization, Resonance, and Aromaticity More About Molecular Orbital Theory

Substitution Reactions of Alkyl Halides

Elimination Reactions of Alkyl Halides Competition Between Substitution and Elimination

Reactions of Alcohols, Ethers, Epoxides, and Sulfur-Containing Compounds

Organometallic Compounds

Reactions of Alkanes, Radicals

Mass Spectrometry, Infrared Spectroscopy, and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Alpha Carbon of Carbonyl Compounds

Reactions of Benzene and Substituted Benzenes

More About Amines Heterocylic Compounds

Carbohydrates

Amino Acids, Peptides, and Proteins

Catalysis

The Organic Mechanisms of the Coenzymes

The Chemistry of Metabolism

Nucleosides, Nucleotides, and Nucleic Acids

Synthetic Polymers

Filters

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