Chapter 11, Problem 21PP

Interpretation Introduction

Interpretation:

The mechanistic explanation for the given reaction is to be provided.

Concept introduction:

Electrophiles are electron deficient species that have positive or partially positive charge. Lewis acids are electrophiles that accept electron pair.

Nucleophiles are electron rich species that have negative or partially negative charge. Lewis bases are nucleophiles that donate electron pair.

Free radical is an atom, molecule, or ion that has unpaired electrons, which makes it highly chemically reactive.

Substitution reaction: A reaction in which one of the hydrogen atoms of a hydrocarbon or a functional group is substituted by any other functional group is called substitution reaction.

Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed is called elimination reaction.

Addition reaction: It is the reaction in which unsaturated bonds are converted to saturated molecules by the addition of molecules.

When a strong nucleophile, such as an alkoxide or a hydroxide ion reacts with an epoxide ring, the later gets opened.

The reaction proceeds by ${\text{S}}_{\text{N}}\text{2}$ mechanism.

The attack of the alkoxide ion happens at the less hindered carbon atom.

Nucleophilic substitution reaction is a reaction in which an electron rich nucleophile attacks the positive or partial positive charge of an atom or a group of atoms to replace a leaving group.

${\text{S}}_{\text{N}}\text{2}$ reaction is the nucleophilic substitution reaction in which the two components are involved in the rate determining step.

The ${\text{S}}_{\text{N}}\text{2}$mechanism of substitution reaction occurs in secondary alkyl halides with an inversion of configuration.

The ${\text{S}}_{\text{N}}\text{2}$reaction takes place in one step. The nucleophile attacks the alkyl halide from the side opposite to the leaving group, resulting in an inversion of configuration.

An ${\text{S}}_{\text{N}}1$ reaction is a nucleophilic substitution reaction in which only one component is involved in the rate-determining step.

The nucleophilic substitutions in which a nucleophile replaces a leaving group are known as ${\text{S}}_{\text{N}}1$ reactions.

${\text{S}}_{\text{N}}1$ reactions are unimolecular as the rate of reaction is dependent on the concentration of a single reactant.

The stability of carbocation: ${\text{3}}^{\text{o}}\text{carbocation}\text{>}{\text{2}}^{\text{o}}\text{carbocation}{\text{>1}}^{\text{o}}\text{carbocation}\text{>methyl}\text{carbocation}$

Epoxide ring opens on reaction with alkanols.

Epoxide ring opens when halide ions react with epoxide followed by hydrolysis.

Epoxide ring opens on reaction with ammonia.