Question 1

Which of the following indicated C-C bonds is(are) the shortest?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  both I and II 
A)  I 
B)  II 
C)  III 
D)  both I and II

Question 2

Which of the following compounds have isolated double bonds?

Accepted Answer

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

Question 3

The following Diels-Alder reaction product is an intermediate in the synthesis of cholesterol. Provide the structure of the product.

Accepted Answer

The answer of The following Diels-Alder reaction product is an...

Question 4

Vitamin D3 has the following structure. Classify the $\pi$ bonds in vitamin D3 as conjugated, cumulated or isolated.

Accepted Answer

The answer of Vitamin D3 has the following structure. Classify...

Question 5

Predict the product for the following Cope rearrangement and provide the curved arrow mechanism for the formation of the product.

Accepted Answer

@#IMG-DLM&_TB4454_00

Question 6

Which of the following best describes the stereochemistry of ring closure and the product for the following reaction?

Accepted Answer

A)  disrotatory, cis-5,6-diethyl-1,3-cyclohexadiene 
B)  conrotatory, cis-5,6-diethyl-1,3-cyclohexadiene 
C)  disrotatory, trans-5,6-diethyl-1,3-cyclohexadiene 
D)  conrotatory, trans -5,6-diethyl-1,3-cyclohexadiene 
A)  disrotatory, cis-5,6-diethyl-1,3-cyclohexadiene 
B)  conrotatory, cis-5,6-diethyl-1,3-cyclohexadiene 
C)  disrotatory, trans-5,6-diethyl-1,3-cyclohexadiene 
D)  conrotatory, trans -5,6-diethyl-1,3-cyclohexadiene

Question 7

What is the IUPAC name for the following compound?

Accepted Answer

A)  (2E, 4Z)-2,4-hexadiene 
B)  (2E, 4Z)-1,4-dimethyl-1,3-butadiene 
C)  (2Z, 4Z)-1,4-dimethyl-1,3-butadiene 
D)  (2Z, 4Z)-2,4-hexadiene 
E)  None of these 
A)  (2E, 4Z)-2,4-hexadiene 
B)  (2E, 4Z)-1,4-dimethyl-1,3-butadiene 
C)  (2Z, 4Z)-1,4-dimethyl-1,3-butadiene 
D)  (2Z, 4Z)-2,4-hexadiene 
E)  None of these

Question 8

Identify the pericyclic reaction in which two sigma bonds are formed and two pi bonds are broken.

Accepted Answer

A)  sigmatropic rearrangement 
B)  cycloaddition reaction 
C)  electrolytic reaction 
D)  this is not a pericyclic reaction 
A)  sigmatropic rearrangement 
B)  cycloaddition reaction 
C)  electrolytic reaction 
D)  this is not a pericyclic reaction

Question 9

Which of the following compounds have conjugated double bonds?

Accepted Answer

A)  II and V 
B)  II, IV, and V 
C)  I and III 
D)  I, III, and IV 
E)  all of them 
A)  II and V 
B)  II, IV, and V 
C)  I and III 
D)  I, III, and IV 
E)  all of them

Question 10

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&_TB4454_00 This reaction is under thermo

Question 11

Predict the major product for the following Diels-Alder reaction.

Accepted Answer

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

Question 12

What is the IUPAC name for the following compound?

Accepted Answer

A)  (2E,4Z,6
E) -3,4,7,8-tetramethyl-2,4,6-heptatriene 
B)  (2Z,4
E) -3,4,7-trimethyl-2,4,6-octatriene 
C)  (2E,4Z,6
E) -2,5,6,7-tetramethyl-3,5,7-heptatriene 
D)  (2E,4Z)- 2,5,6-trimethyl-3,5,7-octatriene 
E)  (4E,6
E) -2,5,6-trimethyl-2,4,6-octatriene 
A)  (2E,4Z,6
E) -3,4,7,8-tetramethyl-2,4,6-heptatriene 
B)  (2Z,4
E) -3,4,7-trimethyl-2,4,6-octatriene 
C)  (2E,4Z,6
E) -2,5,6,7-tetramethyl-3,5,7-heptatriene 
D)  (2E,4Z)- 2,5,6-trimethyl-3,5,7-octatriene 
E)  (4E,6
E) -2,5,6-trimethyl-2,4,6-octatriene

Question 13

Which of the following best describes the stereochemistry of ring closure and the product for the following reaction?

Accepted Answer

A)  disrotatory, cis-3,4-diethylcyclobutene 
B)  conrotatory, cis-3,4-diethylcyclobutene 
C)  disrotatory, trans-3,4-diethylcyclobutene 
D)  conrotatory, trans -3,4-diethylcyclobutene 
A)  disrotatory, cis-3,4-diethylcyclobutene 
B)  conrotatory, cis-3,4-diethylcyclobutene 
C)  disrotatory, trans-3,4-diethylcyclobutene 
D)  conrotatory, trans -3,4-diethylcyclobutene

Question 14

Predict the major product for the following Diels-Alder reaction.

Accepted Answer

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

Question 15

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

Question 16

Predict the product for the following electrocyclic reaction.

Accepted Answer

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

Question 17

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 18

Which diene and dienophile would react to give the following Diels-Alder product?

Accepted Answer

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

Question 19

Use Woodward-Fieser rules to estimate the $\lambda$max for the following compound.

Accepted Answer

A)  238 nm 
B)  233 nm 
C)  222 nm 
D)  229 nm 
E)  none of these 
A)  238 nm 
B)  233 nm 
C)  222 nm 
D)  229 nm 
E)  none of these

Question 20

The following diene does not undergo Diels Alder reaction because _____.

Accepted Answer

A)  it does not have an electron donating group 
B)  it does not have an electron withdrawing group 
C)  the bicyclic ring does not function as a diene 
D)  it cannot adopt the s-cis conformation 
E)  the double bonds are not in the same cyclic ring 
A)  it does not have an electron donating group 
B)  it does not have an electron withdrawing group 
C)  the bicyclic ring does not function as a diene 
D)  it cannot adopt the s-cis conformation 
E)  the double bonds are not in the same cyclic ring

Exam 16: Conjugated Pi Systems and Pericyclic Reactions

Which of the following indicated C-C bonds is(are) the shortest?

Which of the following compounds have isolated double bonds?

The following Diels-Alder reaction product is an intermediate in the synthesis of cholesterol. Provide the structure of the product.

Vitamin D3 has the following structure. Classify the π\piπ bonds in vitamin D3 as conjugated, cumulated or isolated.

Predict the product for the following Cope rearrangement and provide the curved arrow mechanism for the formation of the product.

Which of the following best describes the stereochemistry of ring closure and the product for the following reaction?

What is the IUPAC name for the following compound?

Identify the pericyclic reaction in which two sigma bonds are formed and two pi bonds are broken.

Which of the following compounds have conjugated double bonds?

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.

Predict the major product for the following Diels-Alder reaction.

What is the IUPAC name for the following compound?

Which of the following best describes the stereochemistry of ring closure and the product for the following reaction?

Predict the major product for the following Diels-Alder reaction.

Which one of the following dienes is most stable?

Predict the product for the following electrocyclic reaction.

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

Which diene and dienophile would react to give the following Diels-Alder product?

Use Woodward-Fieser rules to estimate the λ\lambdaλ max for the following compound.

The following diene does not undergo Diels Alder reaction because _____.

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

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Alkyl Halides: Nucleophilic Substitution and Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Radical Reactions

Synthesis

Alcohols and Phenols

Ethers and Epoxides; Thiols and Sulfides

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Aromatic Compounds

Aromatic Substitution Reactions

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Alpha Carbon Chemistry: Enols and Enolates

Amines

Introduction to Organometallic Compounds

Carbohydrates

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Vitamin D₃ has the following structure. Classify the $\pi$ bonds in vitamin D₃ as conjugated, cumulated or isolated. $Vitamin D<sub>3</sub> has the following structure. Classify the \pi bonds in vitamin D<sub>3</sub> as conjugated, cumulated or isolated.$

Use Woodward-Fieser rules to estimate the $\lambda$ _max for the following compound. $Use Woodward-Fieser rules to estimate the \lambda <sub>max</sub> for the following compound.$