Question 1

Give the product for the following reaction.

Accepted Answer

A)    
B)    
C)    
D)    
E) no reaction 
A)    
B)    
C)    
D)    
E) no reaction

Question 2

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 3

Give the product for the following thermal reaction.

Accepted Answer

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

Question 4

Which of the following ring formations must involve a suprafacial bond formation?

Accepted Answer

A) four-membered ring 
B) five-membered ring 
C) six-membered ring 
D) A and C 
E) A,B and C 
A) four-membered ring 
B) five-membered ring 
C) six-membered ring 
D) A and C 
E) A,B and C

Question 5

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

Accepted Answer

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

Question 6

Consider the π molecular orbitals of pentadienyl cation and answer the following questions.Please refer to the lowest π MO as ψ1.
a)How many π molecular orbitals of pentadienyl cation are bonding?
b)Which π molecular orbital is the HOMO?
c)Which π molecular orbitals are asymmetric with respect to a mirror plane perpendicular to the molecular plane?

Accepted Answer

a)ψ₁ and ψ₂

Question 7

Under what conditions would a 1,3-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 8

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 9

Give the conditions for 1,5-hydrogen shifts.You may choose more than one answer.

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 10

What does LCAO stand for?

Accepted Answer

Linear com

Question 11

Fill in the empty boxes.

Accepted Answer

Diels-Alde

Question 12

Give the product for the following reaction.

Accepted Answer

A)    
B)    
C)    
D)    
E) no reaction 
A)    
B)    
C)    
D)    
E) no reaction

Question 13

Under thermal 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 14

What is the product of the following 1,5-hydrogen shift? CH3CH   CHCH   CD2   ?

Accepted Answer

A) CH2     CHCH2CH   CHD 
B) CH2     CHCH   CHCHD2 
C) CHD   CHCH   CHCH3 
D) CH2     CHCH2CH2CH2D 
E) CH2     CHCH   CHCD3 
A) CH2     CHCH2CH   CHD 
B) CH2     CHCH   CHCHD2 
C) CHD   CHCH   CHCH3 
D) CH2     CHCH2CH2CH2D 
E) CH2     CHCH   CHCD3

Question 15

Which of the following best explains the rearrangement when provitamin D3 rearranges to vitamin D3?

Accepted Answer

A) [1,7] cycloaddition rearrangement,antarafacial 
B) [1,7] cycloaddition rearrangement,suprafacial 
C) [1,7] sigmatropic rearrangement,antarafacial 
D) [1,7] sigmatropic rearrangement,suprafacial 
E) [1,7] electrocyclic reaction,suprafacial 
A) [1,7] cycloaddition rearrangement,antarafacial 
B) [1,7] cycloaddition rearrangement,suprafacial 
C) [1,7] sigmatropic rearrangement,antarafacial 
D) [1,7] sigmatropic rearrangement,suprafacial 
E) [1,7] electrocyclic reaction,suprafacial

Question 16

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 17

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 18

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 19

Describe a cycloaddition reaction.

Accepted Answer

A) The reactant has lost a sigma bond,the product has a new sigma bond,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) The reactant has lost a sigma bond,the product has a new sigma bond,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 20

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

Exam 28: Pericyclic Reactions

Give the product for the following reaction.

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

Give the product for the following thermal reaction.

Which of the following ring formations must involve a suprafacial bond formation?

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

Under what conditions would a 1,3-hydrogen shift occur in a sigmatropic rearrangement?

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

Give the conditions for 1,5-hydrogen shifts.You may choose more than one answer.

What does LCAO stand for?

Fill in the empty boxes.

Give the product for the following reaction.

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

What is the product of the following 1,5-hydrogen shift? CH3CH CHCH CD2 ?

Which of the following best explains the rearrangement when provitamin D3 rearranges to vitamin D3?

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

Which of the following statements best describes the term suprafacial?

Describe a Claisen rearrangement.

Describe a cycloaddition reaction.

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

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

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

What is the product of the following 1,5-hydrogen shift? CH₃CH CHCH CD₂ ?

Which of the following best explains the rearrangement when provitamin D₃ rearranges to vitamin D₃?