Question 1

What are the two modes of bond formation in cycloaddition reactions?

Accepted Answer

A)  suprafacial and antarafacial bond formations. 
B)  superfacial and antifacial bond formations. 
C)  suprafacial and synfacial bond formations. 
D)  synfacial and antifacial bond formations. 
A)  suprafacial and antarafacial bond formations. 
B)  superfacial and antifacial bond formations. 
C)  suprafacial and synfacial bond formations. 
D)  synfacial and antifacial bond formations.

Question 2

How many bonding molecular orbitals are present in 1,3,5,7,9-decapentaene?

Accepted Answer

A)  4 
B)  5 
C)  10 
D)  12 
A)  4 
B)  5 
C)  10 
D)  12

Question 3

Which of the following statements about cycloaddition reactions is not true?

Accepted Answer

A)  Cycloaddition reactions form a cyclic product with two new F1F1F1S1F1F1F10 bonds. 
B)  The course of the reaction is determined by the symmetry of the molecular orbitals of the products. 
C)  Cycloaddition reactions are concerted. 
D)  Cycloaddition reactions are stereospecific. 
A)  Cycloaddition reactions form a cyclic product with two new F1F1F1S1F1F1F10 bonds. 
B)  The course of the reaction is determined by the symmetry of the molecular orbitals of the products. 
C)  Cycloaddition reactions are concerted. 
D)  Cycloaddition reactions are stereospecific.

Question 4

What is the major organic product of the following oxy-Cope rearrangement?

Accepted Answer

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

Question 5

What is the major organic product of the following Cope rearrangement?

Accepted Answer

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

Question 6

How many nodes are present in F1F1F1S1F1F1F105 of 1,3,5,7,9-decapentaene?

Accepted Answer

A)  2 
B)  3 
C)  4 
D)  5 
A)  2 
B)  3 
C)  4 
D)  5

Question 7

Which of the following statements about [2+2] cycloaddition reactions between two alkenes is true?

Accepted Answer

A)  The reaction is initiated by heat. 
B)  The reaction is initiated by light. 
C)  The product is a cyclopentane derivative. 
D)  Each reactant contains two F1F1F1S1F1F1F10 electrons that participate in the formation of new bonds. 
A)  The reaction is initiated by heat. 
B)  The reaction is initiated by light. 
C)  The product is a cyclopentane derivative. 
D)  Each reactant contains two F1F1F1S1F1F1F10 electrons that participate in the formation of new bonds.

Question 8

What is the correct classification of the following reaction?

Accepted Answer

A)  cycloaddition reaction 
B)  electrocyclic reaction 
C)  electrophilic reaction 
D)  sigmatropic reaction 
A)  cycloaddition reaction 
B)  electrocyclic reaction 
C)  electrophilic reaction 
D)  sigmatropic reaction

Question 9

Which of the following statements about a F1F1F1S1F1F1F10* antibonding molecular orbital is true?

Accepted Answer

A)  A F1F1F1S1F1F1F10* antibonding molecular orbital is formed when two p orbitals of similar phase overlap. 
B)  A F1F1F1S1F1F1F10* antibonding molecular orbital is formed when two p orbitals of opposite phase overlap. 
C)  A F1F1F1S1F1F1F10* antibonding molecular orbital is a higher-energy molecular orbital than a F1F1F1S1F1F1F10 bonding molecular orbital. 
D)  Both the statements "a F1F1F1S1F1F1F10* antibonding molecular orbital is formed when two p orbitals of opposite phase overlap" and "a F1F1F1S1F1F1F10* antibonding molecular orbital is a higher-energy molecular orbital than a F1F1F1S1F1F1F10 bonding molecular orbital" are true. 
A)  A F1F1F1S1F1F1F10* antibonding molecular orbital is formed when two p orbitals of similar phase overlap. 
B)  A F1F1F1S1F1F1F10* antibonding molecular orbital is formed when two p orbitals of opposite phase overlap. 
C)  A F1F1F1S1F1F1F10* antibonding molecular orbital is a higher-energy molecular orbital than a F1F1F1S1F1F1F10 bonding molecular orbital. 
D)  Both the statements "a F1F1F1S1F1F1F10* antibonding molecular orbital is formed when two p orbitals of opposite phase overlap" and "a F1F1F1S1F1F1F10* antibonding molecular orbital is a higher-energy molecular orbital than a F1F1F1S1F1F1F10 bonding molecular orbital" are true.

Question 10

What is the organic product of the following electrocyclic reaction?

Accepted Answer

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

Question 11

Which of the following statements about an electrocyclic ring-opening reaction is not true?

Accepted Answer

A)  An electrocyclic ring-opening reaction is an intramolecular reaction. 
B)  An electrocyclic ring-opening reaction requires a source of energy (heat or light). 
C)  The product of an electrocyclic ring-opening reaction contains one fewer F1F1F1S1F1F1F10 bond than the reactant. 
D)  The product of an electrocyclic ring-opening reaction contains one more F1F1F1S1F1F1F10 bond than the reactant. 
A)  An electrocyclic ring-opening reaction is an intramolecular reaction. 
B)  An electrocyclic ring-opening reaction requires a source of energy (heat or light). 
C)  The product of an electrocyclic ring-opening reaction contains one fewer F1F1F1S1F1F1F10 bond than the reactant. 
D)  The product of an electrocyclic ring-opening reaction contains one more F1F1F1S1F1F1F10 bond than the reactant.

Question 12

Which of the following statements about electrocyclic ring closure is not true?

Accepted Answer

A)  It is an intramolecular reaction. 
B)  It requires heat or light. 
C)  The cyclic product contains one more F1F1F1S1F1F1F10 bond and one fewer F1F1F1S1F1F1F10 bond than the reactants. 
D)  The cyclic product contains one more F1F1F1S1F1F1F10 bond and one fewer F1F1F1S1F1F1F10 bond than the reactants. 
A)  It is an intramolecular reaction. 
B)  It requires heat or light. 
C)  The cyclic product contains one more F1F1F1S1F1F1F10 bond and one fewer F1F1F1S1F1F1F10 bond than the reactants. 
D)  The cyclic product contains one more F1F1F1S1F1F1F10 bond and one fewer F1F1F1S1F1F1F10 bond than the reactants.

Exam 27: Pericyclic Reactions

What are the two modes of bond formation in cycloaddition reactions?

How many bonding molecular orbitals are present in 1,3,5,7,9-decapentaene?

Which of the following statements about cycloaddition reactions is not true?

What is the major organic product of the following oxy-Cope rearrangement?

What is the major organic product of the following Cope rearrangement?

How many nodes are present in 5 of 1,3,5,7,9-decapentaene?

Which of the following statements about [2+2] cycloaddition reactions between two alkenes is true?

What is the correct classification of the following reaction?

Which of the following statements about a * antibonding molecular orbital is true?

What is the organic product of the following electrocyclic reaction?

Which of the following statements about an electrocyclic ring-opening reaction is not true?

Which of the following statements about electrocyclic ring closure is not true?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers and Epoxides

Alkenes

Alkynes

Oxidation and Reduction

Mass Spectrometry and Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Radical Reactions

Conjugation, Resonance, and Dienes

Benzene and Aromatic Compounds

Electrophilic Aromatic Substitution

Carboxylic Acids and the Acidity of the O-H Bond

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones Nucleophilic Addition

Carboxylic Acids and Derivatives

Substitution Reactions of Carbonyl Compounds at the Alpha-Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond Forming Reactions in Organic Synthesis

Carbohydrates

Amino Acids and Proteins

Lipids

Synthetic Polymers

Filters

How many nodes are present in ₅ of 1,3,5,7,9-decapentaene?