Chapter 16, Problem 16.55AP

Interpretation Introduction

(a)

Interpretation:

The curved arrow mechanism of the formation of compound A is to be stated.

Concept introduction:

Alkyl halides undergo elimination reaction in the presence of a base to form alkenes. The mechanism of the reaction followed depends on the base used. The most substituted alkene is formed as the major product according to Zaitsev rule. According to Zaitsev rule, in E1 reactions, the more substituted or more alkylated alkene is the major product as it is more stable.

Interpretation Introduction

(b)

Interpretation:

The three basic steps of electrophilic aromatic substitution in the mechanism are to be stated.

Concept introduction:

An electrophile is a positive species which has an affinity towards negative charge.

The chemical reaction in which a functional group is displaced by an electrophile is called the electrophilic substitution reaction. When the electrophilic substitution happens on an aromatic ring such as benzene then the reaction is known as electrophilic aromatic substitution. An electrophile is a positive species which has an affinity towards negative charge and a nucleophile is a negative species which has an affinity towards a positive charge.

Interpretation Introduction

(c)

Interpretation:

The product obtained if the reaction b followed the usual directing effects of alkyl substituents is to be stated. A reason as to why the celestolide instead of the expected product is formed is to be suggested.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.