Question 1

Classify the following reaction.

Accepted Answer

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

Question 2

Exhibit 30-8
Classify each of the following sigmatropic reactions by order [x, y].
26.   ANSWER:
[3, 3]   POINTS:
1
27.   ANSWER:
[1, 7]   POINTS:
1
28.   ANSWER:
[1, 5]   POINTS:
1
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 3

Define a pericyclic reaction.

Accepted Answer

A concerted reaction through a

Question 4

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...

Question 5

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 6

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

Question 7

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 8

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 9

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.

Question 10

To answer the following question(s), consider the π molecular orbitals of a conjugated diene shown below:  
-Draw the product(s) you would expect to obtain from photochemical cyclization of (2Z, 4E)-hexadiene.

Accepted Answer

The answer of To answer the following question(s), consider the...

Question 11

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 12

Classify the following reaction.

Accepted Answer

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

Question 13

Exhibit 30-5
To answer the following question(s), consider the reaction below:  
-Refer to Exhibit 30-5. What type of pericyclic reaction is involved in this transformation?

Accepted Answer

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

Question 14

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 hydrogens to

Question 15

To answer the following question(s), consider the π molecular orbitals of a conjugated diene shown below:  
-Refer to Exhibit 30-1. Which molecular orbital of a conjugated diene contains two nodes between nuclei?

Accepted Answer

A)  ψ1 
B)  ψ2 
C)  ψ3* 
D)  ψ4* 
A)  ψ1 
B)  ψ2 
C)  ψ3* 
D)  ψ4*

Question 16

For an odd number of electron pairs (double bonds), for cycloadditions reactions which of the following rules is correct?:

Accepted Answer

A)  thermal conditions - antarafacial, photochemical conditions - suprafacial 
B)  thermal conditions - suprafacial, photochemical conditions - antarafacial 
A)  thermal conditions - antarafacial, photochemical conditions - suprafacial 
B)  thermal conditions - suprafacial, photochemical conditions - antarafacial

Question 17

Exhibit 30-7
Consider the Sommelet-Hauser rearrangement below to answer the following question(s):  
-Refer to Exhibit 30-7. Would you expect the Sommelet-Hauser rearrangement to be antarafacial or suprafacial? Explain.

Accepted Answer

Since three pairs of electrons

Question 18

Exhibit 30-6
Consider the reaction sequence below to answer the following question(s):  
-Refer to Exhibit 30-6. Explain the stereochemistry of product C.

Accepted Answer

Step 2 is a thermal [1, 5] sig

Question 19

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 20

Exhibit 30-6
Consider the reaction sequence below to answer the following question(s):  
-Refer to Exhibit 30-6. Explain the stereochemistry of product B.

Accepted Answer

Step 1 is the thermal electroc

Exam 26: Orbitals and Organic Chemistry: Pericyclic Reactionse

Classify the following reaction.

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

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?

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

Under photochemical conditions, the following substance will undergo:

Which of the following is not an electrocyclic reaction?

To answer the following question(s), consider the π molecular orbitals of a conjugated diene shown below: -Draw the product(s) you would expect to obtain from photochemical cyclization of (2Z, 4E)-hexadiene.

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.

Classify the following reaction.

Exhibit 30-5 To answer the following question(s), consider the reaction below: -Refer to Exhibit 30-5. What type of pericyclic reaction is involved in this transformation?

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?

To answer the following question(s), consider the π molecular orbitals of a conjugated diene shown below: -Refer to Exhibit 30-1. Which molecular orbital of a conjugated diene contains two nodes between nuclei?

For an odd number of electron pairs (double bonds), for cycloadditions reactions which of the following rules is correct?:

Exhibit 30-7 Consider the Sommelet-Hauser rearrangement below to answer the following question(s): -Refer to Exhibit 30-7. Would you expect the Sommelet-Hauser rearrangement to be antarafacial or suprafacial? Explain.

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6. Explain the stereochemistry of product C.

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.

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6. Explain the stereochemistry of product B.

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

Alkenes and Alkynes

Reactions of Alkenes and Alkynes

Aromatic Compounds

Structure Determination: Mass Spectrometry, Infrared Spectroscopy, and Ultraviolet Spectroscopy

Structure Determination: Mass Spectrometry, Infrared Spectroscopy, and Ultraviolet Spectroscopy

Structure Determination: Nuclear Magnetic Resonance Spectroscopy

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols, Phenols, and Thiols; Ethers and Sulfides

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Nitriles

Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution and Condensation Reactions

Amines and Heterocycles

Biomolecules: Amino Acids, Peptides, and Proteins

Amino Acid Metabolism

Biomolecules: Carbohydrates

Carbohydrate Metabolism

Biomolecules: Lipids and Their Metabolism

Biomolecules: Nucleic Acids and Their Metabolism

Synthetic Polymerse

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