Question 1

Which of the following statements about sigmatropic rearrangements and orbital symmetry is not true?

Accepted Answer

A) Reactions involving six atoms or fewer must take place by suprafacial pathways. 
B) In a suprafacial rearrangement,the new s bond forms on the opposite side of the p system as the broken s bond. 
C) In an antarafacial rearrangement,the new s bond forms on the opposite side of the p system as the broken s bond. 
D) In a suprafacial rearrangement,the new s bond forms on the same side of the p system as the broken s bond. 
A) Reactions involving six atoms or fewer must take place by suprafacial pathways. 
B) In a suprafacial rearrangement,the new s bond forms on the opposite side of the p system as the broken s bond. 
C) In an antarafacial rearrangement,the new s bond forms on the opposite side of the p system as the broken s bond. 
D) In a suprafacial rearrangement,the new s bond forms on the same side of the p system as the broken s bond.

Question 2

Why is the Diels-Alder reaction called a thermal [4+2] cycloaddition?

Accepted Answer

A) Because the reaction is initiated by heat; the diene has four p electrons and the dienophile has two p electrons. 
B) Because the reaction is initiated by light; the diene has four p electrons and the dienophile has two p electrons. 
C) Because the reaction is initiated by heat; the dienophile has four p electrons and the diene has two p electrons. 
D) Because the reaction is initiated by light; the dienophile has four p electrons and the diene has two p electrons. 
A) Because the reaction is initiated by heat; the diene has four p electrons and the dienophile has two p electrons. 
B) Because the reaction is initiated by light; the diene has four p electrons and the dienophile has two p electrons. 
C) Because the reaction is initiated by heat; the dienophile has four p electrons and the diene has two p electrons. 
D) Because the reaction is initiated by light; the dienophile has four p electrons and the diene has two p electrons.

Which of the following statements about sigmatropic rearrangements and orbital symmetry is not true?

Why is the Diels-Alder reaction called a thermal [4+2] cycloaddition?

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 Related Compounds

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Conjugation, resonance, and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives - Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Molecular Ion Peaks and Fragmentation Patterns

Analyzing Molecular Motion and Infrared Spectroscopy

Organic Spectroscopy Concepts

Filters

Exam 25: Pericyclic Reactions

Which of the following statements about sigmatropic rearrangements and orbital symmetry is not true?

Why is the Diels-Alder reaction called a thermal [4+2] cycloaddition?

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 Related Compounds

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Conjugation, resonance, and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives - Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Molecular Ion Peaks and Fragmentation Patterns

Analyzing Molecular Motion and Infrared Spectroscopy

Organic Spectroscopy Concepts

Filters