Question 1

Dienes with alternate $\pi$ and $\sigma$ bonds are classified as ______.

Accepted Answer

A)  isolated 
B)  cumulated 
C)  skipped 
D)  conjugated 
E)  none of these 
A)  isolated 
B)  cumulated 
C)  skipped 
D)  conjugated 
E)  none of these D

Question 2

Zingiberene, a terpene found in ginger has the following structure. Classify the  $\pi$ bonds in zingiberene as conjugated, cumulated or isolated.

Accepted Answer

The answer of Zingiberene, a terpene found in ginger has...

Question 3

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

Accepted Answer

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

Question 4

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 5

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& This reaction is under thermodynamic co

Question 6

How many electrons does the HOMO of 1,3-pentadiene have in its excited state?

Accepted Answer

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

Question 7

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 8

Provide the structures of A, B and C for the following reaction sequence.

Accepted Answer

The answer of Provide the structures of A, B and...

Question 9

Identify the color of a compound that absorbs blue light.

Accepted Answer

A)  orange 
B)  green 
C)  red 
D)  blue 
E)  yellow 
A)  orange 
B)  green 
C)  red 
D)  blue 
E)  yellow

Question 10

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

Accepted Answer

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

Question 11

What is the IUPAC name for the following compound?

Accepted Answer

A)  1-chloro-1-methyl-2,5-cyclohexadiene 
B)  3-chloro-3-methyl-1,4-cyclohexadiene 
C)  6-chloro-6-methyl-1,4-cyclohexadiene 
D)  2-chloro-2-methyl-1,3-cyclohexadiene 
E)  None of these 
A)  1-chloro-1-methyl-2,5-cyclohexadiene 
B)  3-chloro-3-methyl-1,4-cyclohexadiene 
C)  6-chloro-6-methyl-1,4-cyclohexadiene 
D)  2-chloro-2-methyl-1,3-cyclohexadiene 
E)  None of these

Question 12

Absorption of UV-visible radiation by a molecule results in___________ transitions.

Accepted Answer

A)  electronic 
B)  nuclear 
C)  rotational 
D)  vibrational 
E)  None of these 
A)  electronic 
B)  nuclear 
C)  rotational 
D)  vibrational 
E)  None of these

Question 13

Predict the major product for the following reaction.

Accepted Answer

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

Question 14

Predict the product for the following Diels-Alder reaction.

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  none of these 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  none of these

Question 15

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 16

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 17

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 18

Predict the major product for the following reaction.

Accepted Answer

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

Question 19

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 dienophile 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 dienophile favor product formation.

Question 20

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

Exam 17: Conjugated Pi Systems and Pericyclic Reactions

Dienes with alternate π\piπ and σ\sigmaσ bonds are classified as ______.

Zingiberene, a terpene found in ginger has the following structure. Classify the π\piπ bonds in zingiberene as conjugated, cumulated or isolated.

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

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.

How many electrons does the HOMO of 1,3-pentadiene have in its excited state?

What is the correct classification of the following pericyclic reaction?

Provide the structures of A, B and C for the following reaction sequence.

Identify the color of a compound that absorbs blue light.

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

What is the IUPAC name for the following compound?

Absorption of UV-visible radiation by a molecule results in___________ transitions.

Predict the major product for the following reaction.

Predict the product for the following Diels-Alder reaction.

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

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

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

Predict the major product for the following reaction.

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

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

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

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

Carbohydrates

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Dienes with alternate $\pi$ and $\sigma$ bonds are classified as ______.

Zingiberene, a terpene found in ginger has the following structure. Classify the $\pi$ bonds in zingiberene as conjugated, cumulated or isolated. $Zingiberene, a terpene found in ginger has the following structure. Classify the \pi bonds in zingiberene as conjugated, cumulated or isolated.$

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