Question 1

Give the 2 + 2 cycloaddition reaction of thymine.

Accepted Answer

The answer of Give the 2 + 2 cycloaddition reaction...

Question 2

Provide the structure of the product.

Accepted Answer

The answer of Provide the structure of the product. ...

Question 3

What is the major product of the following [3,3] sigmatropic rearrangement?

Accepted Answer

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

Question 4

What pericyclic photochemical reaction can lead to skin cancer in humans? Draw the structure of the compounds involved in the reaction,and explain how this reaction leads to skin cancer.

Accepted Answer

Thymine dimerization. At any point in DN

Question 5

Show the mechanism for each of the following pericyclic reactions.

Accepted Answer

The answer of Show the mechanism for each of the...

Question 6

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

Accepted Answer

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

Question 7

Provide the structure of the diene and dienophile for the preparation of the following compound.

Accepted Answer

The answer of Provide the structure of the diene and...

Question 8

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 9

Give the product(s)for the following reaction.You may choose more than one answer.

Accepted Answer

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

Question 10

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 11

Which of the following molecular orbitals are formed from subtractive overlap of atomic orbitals?

Accepted Answer

A) antibonding orbitals 
B) out-of-phase orbitals 
C) bonding orbitals 
D) A and B 
E) B and C 
A) antibonding orbitals 
B) out-of-phase orbitals 
C) bonding orbitals 
D) A and B 
E) B and C

Question 12

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 13

How would you synthesize the following compound and its enantiomer from butadiene and ethylene?

Accepted Answer

Diels-Alde

Question 14

How many π molecular orbitals does 1,3,5,7-octatetraene have?

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 10 
A) 2 
B) 4 
C) 6 
D) 8 
E) 10

Question 15

Under photochemical 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 16

Show the mechanism for the following 1,3-hydrogen shift.

Accepted Answer

The answer of Show the mechanism for the following 1,3-hydrogen...

Question 17

Give the product for the following reaction.

Accepted Answer

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

Question 18

Which of the following statements concerning the selection rules for pericyclic reactions is correct?

Accepted Answer

A) If TE describes the reaction,then the outcome is given by AC. 
B) If PO describes the reaction,then the outcome is given by AC. 
C) If TO describes the reaction,then the outcome is given by AC. 
D) both A and B 
E) none of the above 
A) If TE describes the reaction,then the outcome is given by AC. 
B) If PO describes the reaction,then the outcome is given by AC. 
C) If TO describes the reaction,then the outcome is given by AC. 
D) both A and B 
E) none of the above

Question 19

Consider the possible thermal [4+4] cycloaddition of two molecules of 1,3-butadiene to generate cycloocta-1,5-diene.Show the HOMO/LUMO interaction which would result,and use this interaction to predict whether the proposed cycloaddition could occur.

Accepted Answer

The answer of Consider the possible thermal [4+4] cycloaddition of...

Question 20

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

Accepted Answer

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

Exam 28: Pericyclic Reactions

Give the 2 + 2 cycloaddition reaction of thymine.

Provide the structure of the product.

What is the major product of the following [3,3] sigmatropic rearrangement?

What pericyclic photochemical reaction can lead to skin cancer in humans? Draw the structure of the compounds involved in the reaction,and explain how this reaction leads to skin cancer.

Show the mechanism for each of the following pericyclic reactions.

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

Provide the structure of the diene and dienophile for the preparation of the following compound.

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(s)for the following reaction.You may choose more than one answer.

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

Which of the following molecular orbitals are formed from subtractive overlap of atomic orbitals?

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

How would you synthesize the following compound and its enantiomer from butadiene and ethylene?

How many π molecular orbitals does 1,3,5,7-octatetraene have?

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

Show the mechanism for the following 1,3-hydrogen shift.

Give the product for the following reaction.

Which of the following statements concerning the selection rules for pericyclic reactions is correct?

Consider the possible thermal [4+4] cycloaddition of two molecules of 1,3-butadiene to generate cycloocta-1,5-diene.Show the HOMO/LUMO interaction which would result,and use this interaction to predict whether the proposed cycloaddition could occur.

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

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds: Nomenclature, physical Properties, and Structure

Isomers: the Arrangement of Atoms in Space

Alkenes: Structure,nomenclature,and an Introduction to Reactivity - Thermodynamics and Kinetics

The Reactions of Alkenes - the Stereochemistry of Addition Reactions

The Reactions of Alkynes - Introduction to Multistep Synthesis

Delocalized Electrons: Their Effect on Stability, pka, and the Products of a Reaction - Aromaticity and Electronic Effects: an Introduction to the Reactions of Benzene

Substitution and Elimination Reactions of Alkyl Halides

Reactions of Alcohols, ethers, epoxides, amines and Sulfur-Containing Compounds

Organometallic Compounds

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 Α-Carbon

Reactions of Benzene and Substituted Benzenes

More About Amines - Reactions of Heterocylic Compounds

The Organic Chemistry of Carbohydrates

Amino Acids,peptides,and Proteins

Catalysis in Organic Reactions and in Enzymatic Reactions

The Organic Chemistry of the Coenzymes, compounds Derived From Vitamins

The Organic Chemistry of the Metabolic Pathways

The Organic Chemistry of Lipids

The Chemistry of the Nucleic Acids

Synthetic Polymers

Filters

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