Chapter 17, Problem 53IP

(a)

Interpretation Introduction

Interpretation: Efficient synthesis for the given transformation has to be proposed.

Concept Introduction:

Williamson ether synthesis: This is ether synthesis is an organic reaction used to convert an alcohol and an alkyl halide to an ether using a base condition such as , this mechanism beings with the base abstracting the proton from the alcohol to form an alkaoxide intermediate.

Bromination: In bromination reaction, hydrogen atom of a molecule is replaced by a bromine atom.

In a reaction, $NBS$ (N-bromo succinimde) is used to introduce bromide ion in a compound

(b)

Interpretation Introduction

Interpretation: Efficient synthesis for the given transformation has to be proposed.

Concept Introduction:

Dehydration reaction:

Removal of water molecule from the reaction when the alcohol is treated with strong acid like sulfuric acid.

  

Alcohol is reaction with concentrated sulfuric acid, first alcohol gets protonated forms carbocation (more stable carbocation) followed by elimination of proton (${\text{H}}^{\text{+}}$) yields alkene as a product. The stability of carbocation is given below,

Tertiary carbocation is more stable than the secondary, secondary carbocation is more stable than primary.

In dehydration reaction, sulfuric acid is act as a proton donor, and which is used to protonate the alcohol and makes carbocation therefore sulfuric acid is the driving force of the reaction. Dehydration reaction will not go without acid (sulfuric acid).

Hydroboration reaction: The reaction involves addition of $B{H}_3$ over alkene which makes $B{H}_2$ to bond with less substituted position of carbon-carbon double bonds and $H$ to more substituted position of carbon-carbon double bonds which finally carbon containing $B{H}_2$ gets oxidized in order to achieve the product with less substitution.

Anti-Markovnikov’s Addition Rule: The unsymmetrical alkene in a chemical compound reacts with hydrogen halide in a way, where halide ions attacks and bond to the less substitution position of carbon-carbon double bond.

In a reaction, fuming sulfuric acid is used to introduce sulfonic groups in a compound (sulfonation) or as dehydrating agent (removing of water molecule).

(c)

Interpretation Introduction

Interpretation: Efficient synthesis for the given transformation has to be proposed.

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.

Structure of the substrate plays major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted then the rate of the reaction will becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate, it depends on steric factor that if more groups attached near the leaving group the reactivity becomes slower.

In a reaction, $NBS$ (N-bromo succinimde) is used to introduce bromide ion in a compound