Chapter 7.13, Problem 44PTS

Interpretation Introduction

Interpretation:

The complete retrosynthesis analysis should be provided for the given target molecule.

Concept Introduction:

Retrosynthesis: The synthesising a target molecule a synthetic route must be designed to give a pure sample of the target molecule using a convenient and efficient method.

A logical approach for designing organic synthesis which involves breaking down of the target molecule into available starting materials by imaginary breaking of bonds ( Disconnection) and or by functional group interconversions (FGI) is known as disconnection approach or retrosynthetic analysis or retrosynthesis or synthesis backwards.

${\text{S}}_{\text{N}}2$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.

${\text{S}}_{\text{N}}\text{1}$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   reaction. The increasing stability order of carbocation is as follows,

Primary carbocation < secondary carbocation < tertiary carbocation

Leaving group: it is a fragment that leaves substrate with a pair of electrons via heterolytic bond cleavage.

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