Chapter 6.9, Problem 13PTS

(a)

Interpretation Introduction

Interpretation:

The sequence of arrow-pushing pattern in the given multi step reaction has to be identified.

Concept Introduction:

Mechanism of the reaction is the step-by-step description of the process by which reactants are changed into products.

There are only four characteristic patterns, and all ionic mechanisms are simply combinations of these four steps, and they are,

1. (1) Nucleophilic attack

When we identify a nucleophilic site and an electrophilic site, the arrow in the mechanism step shows the nucleophile attacking.

1. (2) Proton transfer
2. (3) Loss of leaving group
3. (4) Rearrangements

Rearrangements will always occur when an alkyl group or hydrogen can shift to form a more stable carbocation. There are mainly two types of rearrangement shifts and they are,

$\begin{array}{l}\text{1, 2-methyl shift}\hfill \\ \text{1, 2-hydride shift}\hfill \end{array}$

Curved arrows show the bonds that are formed and the bonds that are broken in a reaction.

Curved arrows used to understand a reaction mechanism.

Curved arrows are drawn to show how the electrons move as new covalent bonds are formed existing covalent bonds are broken.

Each arrow represents the simultaneous movement of two electrons from a nucleophile towards an electrophile.

Nucleophile: It is negatively charged species which seeks for positive charge and hence donate pair of electrons to positively charged species (electrophiles) which results in the formation of chemical bond.

(b)

Interpretation Introduction

Interpretation:

The sequence of arrow-pushing pattern in the given multi step reaction has to be identified.

Concept Introduction:

Mechanism of the reaction is the step-by-step description of the process by which reactants are changed into products.

There are only four characteristic patterns, and all ionic mechanisms are simply combinations of these four steps, and they are,

1. (1) Nucleophilic attack

When we identify a nucleophilic site and an electrophilic site, the arrow in the mechanism step shows the nucleophile attacking.

1. (2) Proton transfer
2. (3) Loss of leaving group
3. (4) Rearrangements

Rearrangements will always occur when an alkyl group or hydrogen can shift to form a more stable carbocation. There are mainly two types of rearrangement shifts and they are,

$\begin{array}{l}\text{1, 2-methyl shift}\hfill \\ \text{1, 2-hydride shift}\hfill \end{array}$

Curved arrows show the bonds that are formed and the bonds that are broken in a reaction.

Curved arrows used to understand a reaction mechanism.

Curved arrows are drawn to show how the electrons move as new covalent bonds are formed existing covalent bonds are broken.

Each arrow represents the simultaneous movement of two electrons from a nucleophile towards an electrophile.

Nucleophile: It is negatively charged species which seeks for positive charge and hence donate pair of electrons to positively charged species (electrophiles) which results in the formation of chemical bond.

(c)

Interpretation Introduction

Interpretation:

The sequence of arrow-pushing pattern in the given multi step reaction has to be identified.

Concept Introduction:

Mechanism of the reaction is the step-by-step description of the process by which reactants are changed into products.

There are only four characteristic patterns, and all ionic mechanisms are simply combinations of these four steps, and they are,

1. (1) Nucleophilic attack

When we identify a nucleophilic site and an electrophilic site, the arrow in the mechanism step shows the nucleophile attacking.

1. (2) Proton transfer
2. (3) Loss of leaving group
3. (4) Rearrangements

Rearrangements will always occur when an alkyl group or hydrogen can shift to form a more stable carbocation. There are mainly two types of rearrangement shifts and they are,

$\begin{array}{l}\text{1, 2-methyl shift}\hfill \\ \text{1, 2-hydride shift}\hfill \end{array}$

Curved arrows show the bonds that are formed and the bonds that are broken in a reaction.

Curved arrows used to understand a reaction mechanism.

Curved arrows are drawn to show how the electrons move as new covalent bonds are formed existing covalent bonds are broken.

Each arrow represents the simultaneous movement of two electrons from a nucleophile towards an electrophile.

Nucleophile: It is negatively charged species which seeks for positive charge and hence donate pair of electrons to positively charged species (electrophiles) which results in the formation of chemical bond.

(d)

Interpretation Introduction

Interpretation:

The sequence of arrow-pushing pattern in the given multi step reaction has to be identified.

Concept Introduction:

Mechanism of the reaction is the step-by-step description of the process by which reactants are changed into products.

There are only four characteristic patterns, and all ionic mechanisms are simply combinations of these four steps, and they are,

1. (1) Nucleophilic attack

When we identify a nucleophilic site and an electrophilic site, the arrow in the mechanism step shows the nucleophile attacking.

1. (2) Proton transfer
2. (3) Loss of leaving group
3. (4) Rearrangements

Rearrangements will always occur when an alkyl group or hydrogen can shift to form a more stable carbocation. There are mainly two types of rearrangement shifts and they are,

$\begin{array}{l}\text{1, 2-methyl shift}\hfill \\ \text{1, 2-hydride shift}\hfill \end{array}$

Curved arrows show the bonds that are formed and the bonds that are broken in a reaction.

Curved arrows used to understand a reaction mechanism.

Curved arrows are drawn to show how the electrons move as new covalent bonds are formed existing covalent bonds are broken.

Each arrow represents the simultaneous movement of two electrons from a nucleophile towards an electrophile.

Nucleophile: It is negatively charged species which seeks for positive charge and hence donate pair of electrons to positively charged species (electrophiles) which results in the formation of chemical bond.