Question 1

Under thermal conditions,the following substance will undergo:

Accepted Answer

A) disrotatory cyclization. 
B) conrotatory cyclization. 
C) no reaction. 
A) disrotatory cyclization. 
B) conrotatory cyclization. 
C) no reaction. A

Question 2

Exhibit 30-7
Consider the Sommelet-Hauser rearrangement below to answer the following question(s):  
-Refer to Exhibit 30-7.The Sommelet-Hauser rearrangement is an example of a [2,3] sigmatropic rearrangement.How many pairs of electrons are involved in this reaction?

Accepted Answer

A) two 
B) three 
C) four 
D) five 
A) two 
B) three 
C) four 
D) five B

Question 3

The photochemical cycloaddition of the structure below is related to DNA mutations causing skin cancer.Draw the structure of this dimer.Atoms other than carbon and hydrogen are labeled.

Accepted Answer

[2+2] cycloaddition occurs due to photochemical conditions.

Question 4

Exhibit 30-9
Vitamin DS1U1B13S1U1B0,cholecalciferol,is synthesized under the skin by the photochemical pericyclic process shown below.Answer the following question(s) about these reactions.  
-Refer to Exhibit 30-9.The first step in this process is a(n):

Accepted Answer

A) sigmatropic rearrangement 
B) cycloaddition reaction 
C) annulation reaction 
D) electrocyclic reaction 
A) sigmatropic rearrangement 
B) cycloaddition reaction 
C) annulation reaction 
D) electrocyclic reaction

Question 5

Exhibit 30-2
Consider the reaction below to answer the following question(s):  
-Refer to Exhibit 30-2.Has this reaction taken place in a conrotatory manner or in a disrotatory manner?

Accepted Answer

In order for the hyd

Question 6

Exhibit 30-5
To answer the following question(s),consider the reaction below:  
-Refer to Exhibit 30-5.Propose a mechanism for the reaction that fully accounts for the formation of both products.

Accepted Answer

@#IMG-DLM& This reaction occurs with suprafacial s

Question 7

Predict the product of the following reaction.

Accepted Answer

The answer of Predict the product of the following reaction....

Question 8

Exhibit 30-3
To answer the following question(s),consider the reaction below:  
-Refer to Exhibit 30-3.Two pericyclic reactions are involved in this synthesis of compound Y.Draw the structure of intermediate X and name it using IUPAC nomenclature.

Accepted Answer

The answer of Exhibit 30-3
To answer the following question(s),consider the...

Question 9

Exhibit 30-4
Consider the reaction below to answer the following question(s):  
-Refer to Exhibit 30-4.How many pairs of electrons are involved in this pericyclic reaction?

Accepted Answer

A) two 
B) four 
C) eight 
D) sixteen 
A) two 
B) four 
C) eight 
D) sixteen

Question 10

The mnemonic phrase "The Electrons Circle Around",TECA,assists in predicting stereochemistry of pericyclic reactions.Describe application of this mnemonic.

Accepted Answer

The mnemonic TECA assists us in remember

Question 11

In which type of pericyclic reaction is a σ bond broken and a new σ bond formed?

Accepted Answer

A) cycloaddition 
B) photochemical electrocyclic 
C) thermal electrocyclic 
D) sigmatropic rearrangement. 
E) all of the above 
A) cycloaddition 
B) photochemical electrocyclic 
C) thermal electrocyclic 
D) sigmatropic rearrangement. 
E) all of the above

Question 12

Exhibit 30-6
Consider the reaction sequence below to answer the following question(s):  
-Refer to Exhibit 30-6.Show how C is formed from B.

Accepted Answer

The answer of Exhibit 30-6
Consider the reaction sequence below to...

Question 13

Under photochemical conditions,the following substance will undergo:

Accepted Answer

A) disrotatory cyclization. 
B) conrotatory cyclization. 
C) no reaction. 
A) disrotatory cyclization. 
B) conrotatory cyclization. 
C) no reaction.

Question 14

Exhibit 30-2
Consider the reaction below to answer the following question(s):  
-Refer to Exhibit 30-2.Under what conditions,thermal or photochemical,would you carry out this reaction? Explain.

Accepted Answer

For a disrotatory cyclization to occur t

Question 15

Exhibit 30-6
Consider the reaction sequence below to answer the following question(s):  
-Refer to Exhibit 30-6.Step 2 is an example of:

Accepted Answer

A) an electrocyclic reaction. 
B) a cycloaddition reaction. 
C) a sigmatropic rearrangement. 
D) a reverse cycloaddition reaction. 
A) an electrocyclic reaction. 
B) a cycloaddition reaction. 
C) a sigmatropic rearrangement. 
D) a reverse cycloaddition reaction.

Question 16

Exhibit 30-4
Consider the reaction below to answer the following question(s):  
-Refer to Exhibit 30-4.Explain the stereochemistry of this reaction.

Accepted Answer

The reaction of heptafulvene w

Question 17

Exhibit 30-3
To answer the following question(s),consider the reaction below:  
-Refer to Exhibit 30-3.Explain the stereochemistry of compound Y.

Accepted Answer

Thermal electrocyclic opening of the cis

Question 18

For an even number of electron pairs (double bonds),which of the following rules is correct?:

Accepted Answer

A) thermal conditions - controtatory,photochemical conditions - disrotatory 
B) thermal conditions - disrotatory,photochemical conditions - conrotatory 
A) thermal conditions - controtatory,photochemical conditions - disrotatory 
B) thermal conditions - disrotatory,photochemical conditions - conrotatory

Question 19

Exhibit 30-6
Consider the reaction sequence below to answer the following question(s):  
-Refer to Exhibit 30-6.Step 1 is an example of:

Accepted Answer

A) an electrocyclic reaction 
B) a cycloaddition reaction 
C) a sigmatropic rearrangement 
D) a reverse cycloaddition reaction 
A) an electrocyclic reaction 
B) a cycloaddition reaction 
C) a sigmatropic rearrangement 
D) a reverse cycloaddition reaction

Question 20

Which of the following is not an electrocyclic reaction?

Accepted Answer

A)    
B)    
C)    
D)    
E) All are electrocyclic reactions. 
A)    
B)    
C)    
D)    
E) All are electrocyclic reactions.

Exam 30: Orbitals and Organic Chemistry: Pericyclic Reactions

Under thermal conditions,the following substance will undergo:

Exhibit 30-7 Consider the Sommelet-Hauser rearrangement below to answer the following question(s): -Refer to Exhibit 30-7.The Sommelet-Hauser rearrangement is an example of a [2,3] sigmatropic rearrangement.How many pairs of electrons are involved in this reaction?

The photochemical cycloaddition of the structure below is related to DNA mutations causing skin cancer.Draw the structure of this dimer.Atoms other than carbon and hydrogen are labeled.

Exhibit 30-9 Vitamin D3,cholecalciferol,is synthesized under the skin by the photochemical pericyclic process shown below.Answer the following question(s) about these reactions. -Refer to Exhibit 30-9.The first step in this process is a(n):

Exhibit 30-2 Consider the reaction below to answer the following question(s): -Refer to Exhibit 30-2.Has this reaction taken place in a conrotatory manner or in a disrotatory manner?

Exhibit 30-5 To answer the following question(s),consider the reaction below: -Refer to Exhibit 30-5.Propose a mechanism for the reaction that fully accounts for the formation of both products.

Predict the product of the following reaction.

Exhibit 30-3 To answer the following question(s),consider the reaction below: -Refer to Exhibit 30-3.Two pericyclic reactions are involved in this synthesis of compound Y.Draw the structure of intermediate X and name it using IUPAC nomenclature.

Exhibit 30-4 Consider the reaction below to answer the following question(s): -Refer to Exhibit 30-4.How many pairs of electrons are involved in this pericyclic reaction?

The mnemonic phrase "The Electrons Circle Around",TECA,assists in predicting stereochemistry of pericyclic reactions.Describe application of this mnemonic.

In which type of pericyclic reaction is a σ bond broken and a new σ bond formed?

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6.Show how C is formed from B.

Under photochemical conditions,the following substance will undergo:

Exhibit 30-2 Consider the reaction below to answer the following question(s): -Refer to Exhibit 30-2.Under what conditions,thermal or photochemical,would you carry out this reaction? Explain.

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6.Step 2 is an example of:

Exhibit 30-4 Consider the reaction below to answer the following question(s): -Refer to Exhibit 30-4.Explain the stereochemistry of this reaction.

Exhibit 30-3 To answer the following question(s),consider the reaction below: -Refer to Exhibit 30-3.Explain the stereochemistry of compound Y.

For an even number of electron pairs (double bonds),which of the following rules is correct?:

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6.Step 1 is an example of:

Which of the following is not an electrocyclic reaction?

Structure and Bonding

Polar Covalent Bonds;acids and Bases

Organic Compounds: Alkanes and Their Stereochemistry

Organic Compounds: Cycloalkanes and Their Stereochemistry

Stereochemistry at Tetrahedral Centers

An Overview of Organic Reactions

Par 1

Alkenes: Structure and Reactivity

Alkenes: Reactions and Synthesis

Alkynes: an Introduction to Organic Synthesis

Organohalides

Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations

Par 2

Structure Determination: Mass Spectrometry and Infrared Spectroscopy

Structure Determination: Nuclear Magnetic Resonance Spectroscopy

Conjugated Compounds and Ultraviolet Spectroscopy

Par 3

Benzene and Aromaticity

Chemistry of Benzene: Electrophilic Aromatic Substitution

Alcohols and Phenols

Ethers and Epoxides;thiols and Sulfides

Aldehydes and Ketones: Nucleophilic Addition Reactions

Par 4

Carboxylic Acids and Nitriles

Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution Reactions

Carbonyl Condensation Reactions

Par 5

Amines and Heterocycles

Biomolecules: Carbohydrates

Biomolecules: Amino Acids,peptides,and Proteins

Par 7

Biomolecules: Lipids

Biomolecules: Nucleic Acids

The Organic Chemistry of Metabolic Pathways

Synthetic Polymers

Par 1

Filters

Exhibit 30-9 Vitamin D₃,cholecalciferol,is synthesized under the skin by the photochemical pericyclic process shown below.Answer the following question(s) about these reactions. -Refer to Exhibit 30-9.The first step in this process is a(n):