Question 1

Which major product(s)are formed for the following reaction?

Accepted Answer

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

Question 2

Which one of the following dienes is most stable?

Accepted Answer

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

Question 3

Which one of the following dienes is most stable?

Accepted Answer

A) CH3CH=CHCH=CHCH3 
B) CH3CH=CHCH2CH=CH2 
C) CH2=CHCH2CH2CH=CH2 
D) CH2=CHCH(CH3)CH=CH2 
E) CH3CH=C=CHCH2CH3 
A) CH3CH=CHCH=CHCH3 
B) CH3CH=CHCH2CH=CH2 
C) CH2=CHCH2CH2CH=CH2 
D) CH2=CHCH(CH3)CH=CH2 
E) CH3CH=C=CHCH2CH3 A

Question 4

Which one of the following compounds is not a product of reaction between 1,3-butadiene and HBr?

Accepted Answer

A) (S)-3-bromo-1-butene 
B) (R)-3-bromo-1-butene 
C) (
E) -1-bromo-2-butene 
D) (Z)-1-bromo-2-butene 
E) (Z)-2-bromo-2-butene 
A) (S)-3-bromo-1-butene 
B) (R)-3-bromo-1-butene 
C) (
E) -1-bromo-2-butene 
D) (Z)-1-bromo-2-butene 
E) (Z)-2-bromo-2-butene

Question 5

Rank the following dienes in increasing order of stability (least to most).

Accepted Answer

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

Question 6

Which statement is NOT true about the Diels-Alder reaction?

Accepted Answer

A) It is a [4+2] cycloaddition reaction. 
B) The diene must be in the s-cis conformation to react. 
C) Most Diels-Alder reactions are reversible. 
D) It is a sigmatropic rearrangement. 
E) Electron donating groups on the diene and electron withdrawing groups on the dieneophile favor product formation. 
A) It is a [4+2] cycloaddition reaction. 
B) The diene must be in the s-cis conformation to react. 
C) Most Diels-Alder reactions are reversible. 
D) It is a sigmatropic rearrangement. 
E) Electron donating groups on the diene and electron withdrawing groups on the dieneophile favor product formation.

Question 7

Which of the following compound(s)have the longest $\lambda$max?

Accepted Answer

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

Question 8

Which one of the following represents the LUMO of 1,3,5-hexatriene?

Accepted Answer

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

Question 9

Provide the structure for 1,2 addition product for the following reaction and explain why it is a major product rather than 1,4 addition product.

Accepted Answer

@#IMG-DLM& 1,2-product is the major one

Question 10

Which one of the following dienophiles is least reactive in the Diels-Alder reaction?

Accepted Answer

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

Question 11

What is the correct classification of the following pericyclic reaction?

Accepted Answer

A) electrophilic addition 
B) sigmatropic rearrangement 
C) cycloaddition 
D) electrocyclic reaction 
E) C & D 
A) electrophilic addition 
B) sigmatropic rearrangement 
C) cycloaddition 
D) electrocyclic reaction 
E) C & D

Question 12

Which of the following diene(s)can not undergo the Diels-Alder reaction?

Accepted Answer

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

Question 13

What is the correct classification of the following pericyclic reaction?

Accepted Answer

A) electrophilic addition 
B) sigmatropic rearrangement 
C) cycloaddition 
D) electrocyclic reaction 
E) C & D 
A) electrophilic addition 
B) sigmatropic rearrangement 
C) cycloaddition 
D) electrocyclic reaction 
E) C & D

Question 14

Which one of the following dienes will have the least heat of hydrogenation?

Accepted Answer

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

Question 15

Predict the major product for the following reaction.

Accepted Answer

The answer of Predict the major product for the following...

Question 16

How many electrons does the LUMO of 2,4-hexadiene have in its ground state?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 0 
A) 1 
B) 2 
C) 3 
D) 4 
E) 0

Question 17

The Diels Alder reaction is a concerted reaction,which means

Accepted Answer

A) The product contains a cyclic ring 
B) The diene must be in the s-cis conformation to react. 
C) All changes in bonding (bond making and bond breaking)occur simultaneously. 
D) It is an endothermic reaction 
E) Both exo and endo products are formed 
A) The product contains a cyclic ring 
B) The diene must be in the s-cis conformation to react. 
C) All changes in bonding (bond making and bond breaking)occur simultaneously. 
D) It is an endothermic reaction 
E) Both exo and endo products are formed

Question 18

Predict the product for the following reaction.

Accepted Answer

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

Question 19

Predict the possible products for the following reaction and provide a curved arrow mechanism for the formation of these products.

Accepted Answer

The answer of Predict the possible products for the following...

Question 20

How many $\pi$-bonding molecular orbitals does 1,3-pentadiene have?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) none 
A) 1 
B) 2 
C) 3 
D) 4 
E) none

Exam 17: Conjugated Pi Systems and Pericyclic Reactions

Which major product(s)are formed for the following reaction?

Which one of the following dienes is most stable?

Which one of the following dienes is most stable?

Which one of the following compounds is not a product of reaction between 1,3-butadiene and HBr?

Rank the following dienes in increasing order of stability (least to most).

Which statement is NOT true about the Diels-Alder reaction?

Which of the following compound(s)have the longest λ\lambdaλ max?

Which one of the following represents the LUMO of 1,3,5-hexatriene?

Provide the structure for 1,2 addition product for the following reaction and explain why it is a major product rather than 1,4 addition product.

Which one of the following dienophiles is least reactive in the Diels-Alder reaction?

What is the correct classification of the following pericyclic reaction?

Which of the following diene(s)can not undergo the Diels-Alder reaction?

What is the correct classification of the following pericyclic reaction?

Which one of the following dienes will have the least heat of hydrogenation?

Predict the major product for the following reaction.

How many electrons does the LUMO of 2,4-hexadiene have in its ground state?

The Diels Alder reaction is a concerted reaction,which means

Predict the product for the following reaction.

Predict the possible products for the following reaction and provide a curved arrow mechanism for the formation of these products.

How many π\piπ -bonding molecular orbitals does 1,3-pentadiene have?

A Review of General Chemistry: Electrons, Bonds, and Molecular Properties

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Substitution Reactions

Alkenes: Structure and Preparation Via Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Radical Reactions

Synthesis

Alcohols and Phenols

Ethers and Epoxides; Thiols and Sulfides

Nuclear Magnetic Resonance Spectroscopy

Infrared Spectroscopy and Mass Spectrometry

Aromatic Compounds

Aromatic Substitution Reactions

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Alpha Carbon Chemistry: Enols and Enolates

Amines

Carbohydrates

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

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Which of the following compound(s)have the longest $\lambda$ _max? $Which of the following compound(s)have the longest \lambda <sub>max</sub>?$

How many $\pi$ -bonding molecular orbitals does 1,3-pentadiene have?