Chapter 20, Problem 20.15P

(a)

Interpretation Introduction

Interpretation: The important resonance hybrids for the given allylic carbocations have to be drawn and ranked based on their contributions.

Concept Introduction:

Allylic systems:

The allylic system is characterized by the connectivity of a single bonded carbon atom connected to double bond alkene functional group as shown here:

Stability of the allylic carbocations:

$\text{Primary}\text{<}\text{Secondary}\text{<}\text{tertiary}$

Example for Primary allylic carbocation is:

Example for Secondary allylic carbocation is:

Example for tertiary allylic carbocation is:

(b)

Interpretation Introduction

Interpretation: The important resonance hybrids for the given allylic carbocations have to be drawn and ranked based on their contributions.

Concept Introduction:

Allylic systems:

The allylic system is characterized by the connectivity of a single bonded carbon atom connected to double bond alkene functional group as shown here:

Stability of the allylic carbocations:

$\text{Primary}\text{<}\text{Secondary}\text{<}\text{tertiary}$

Example for Primary allylic carbocation is:

Example for Secondary allylic carbocation is:

Example for tertiary allylic carbocation is:

(c)

Interpretation Introduction

Interpretation: The important resonance hybrids for the given allylic carbocations have to be drawn and ranked based on their contributions.

Concept Introduction:

Allylic systems:

The allylic system is characterized by the connectivity of a single bonded carbon atom connected to double bond alkene functional group as shown here:

Stability of the allylic carbocations:

$\text{Primary}\text{<}\text{Secondary}\text{<}\text{tertiary}$

Example for Primary allylic carbocation is:

Example for Secondary allylic carbocation is:

Example for tertiary allylic carbocation is: