(a) Interpretation: An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state; (a) According to the following results, two transition states are to be stated. Concept introduction: Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

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Answer 1

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Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

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Answer 2

Question

Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

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Answer 3

Question

Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

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Answer 4

Question

Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

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Answer 5

Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

Answer 6

Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Answer 7

Chapter 28, Problem 28.48AP

Interpretation Introduction

(a)

Interpretation:

An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;

(a) According to the following results, two transition states are to be stated.

Concept introduction:

Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.

Answer 8

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

Answer 9

Interpretation Introduction

(b)

Interpretation:

When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

Answer 10

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Answer 13

Ch. 28 - Prob. 28.1P Ch. 28 - Prob. 28.2P Ch. 28 - Prob. 28.3P Ch. 28 - Prob. 28.4P Ch. 28 - Prob. 28.5P Ch. 28 - Prob. 28.6P Ch. 28 - Prob. 28.7P Ch. 28 - Prob. 28.8P Ch. 28 - Prob. 28.9P Ch. 28 - Prob. 28.10P

Solution Summary: The author explains that an all-suprafacial sigmatropic rearrangement could in principle take place through either a chair-like or an oblique transition state.

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