Chapter 8.5, Problem 14P

(a)

Interpretation Introduction

Interpretation:

The configuration of the substitution products formed from the given reaction has to be drawn.

Concept Introduction:

${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction, which results in the inversion of configuration. Rate of ${\text{S}}_{\text{N}}2$ reaction depends on both alkyl halide and the nucleophile present.

$\text{Rate}\text{= k}\left[\text{alkylhalide}\right]\text{×}\left[\text{nucleophile}\right]$

Structure of the substrate plays a major role in ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted the rate of the reaction becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate it depends on steric factor

Solvolysis: The reaction is defined as solvolysis reaction if solvent acts as nucleophile in the given reaction.

Configuration of a molecule: The configurations of a molecule arise due to the spatial arrangement of atoms. The configuration can be assigned by following CIP rules as follows.

Assign numbering to the groups which are bonded to the chiral carbon based on the molecular weight and electronegativity.

If the sequence of the numbering follows clockwise direction the chiral atom is assigned as R configuration.

If the sequence of the numbering follows anticlockwise direction the chiral atom is assigned as S configuration.

(b)

Interpretation Introduction

Interpretation:

The configuration of the substitution products formed from the given reaction has to be drawn.

Concept Introduction:

${\text{S}}_{\text{N}}\text{1}$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on one reactant. First step is the formation of more stable carbocation which is followed by the attack of nucleophile. Formation of more stable carbocation and the leaving group present in the substrate plays very important role in the reactivity of ${\text{S}}_{\text{N}}\text{1}$ reaction. The increasing stability order of carbocation is as follows,

Primary carbocation < secondary carbocation < tertiary carbocation

Transition State: The state which defines the highest potential energy with respect to reaction co-ordinate between reactant and product. It is usually denoted by using the symbol ‘≠’.

Nucleophile: donates pair of electrons to positively charged substrate resulting in the formation of chemical bond.

Configuration of a molecule: The configurations of a molecule arise due to the spatial arrangement of atoms. The configuration can be assigned by following CIP rules as follows.

Assign numbering to the groups which are bonded to the chiral carbon based on the molecular weight and electronegativity.

If the sequence of the numbering follows clockwise direction the chiral atom is assigned as R configuration.

If the sequence of the numbering follows anticlockwise direction the chiral atom is assigned as S configuration.