Chapter 21, Problem 117CP

(a)

Interpretation Introduction

Interpretation: In the given synthetic scheme, the structures of compounds B and C have to be drawn.

Concept Introduction:

 The given synthetic transformation scheme is shown here:

 For any given transformation, the following mandatory observations have to be made clear to predict the synthetic scheme:

• Observe whether there is any change in the carbon skeleton.
• Observe whether there is any change in the location of the functional group.
• Predict the synthetic scheme in such a way that these two observations have to be achieved within the minimum chemo selective steps.

Tosylation reaction:

The alcohol is treated with any tosyl chloride (methane sulfonyl chloride) which yields tosylated product this reaction is called as alkyl tosylate and which is shown below,

Wittig reaction:

It is the conversion of a ketone or an aldehyde into alkene using the ylide of phosphorus.

General Scheme

(b)

Interpretation Introduction

Interpretation: The conversion C to D has to be explained.

Concept Introduction:

 The given synthetic transformation scheme is shown here:

 For any given transformation, the following mandatory observations have to be made clear to predict the synthetic scheme:

• Observe whether there is any change in the carbon skeleton.
• Observe whether there is any change in the location of the functional group.
• Predict the synthetic scheme in such a way that these two observations have to be achieved within the minimum chemo selective steps.

Tosylation reaction:

The alcohol is treated with any tosyl chloride (methane sulfonyl chloride) which yields tosylated product this reaction is called as alkyl tosylate and which is shown below,

Wittig reaction:

It is the conversion of a ketone or an aldehyde into alkene using the ylide of phosphorus.

General Scheme

Gillman’s reagent:

It is the organometallic reagent that will be widely used to alkylate $\text{α,β}$ unsaturated double bonds.

It is represented as

$\begin{array}{l}{R}_{2}CuLi\\ R-\text{Alkyl}\text{or}\text{aryl}\end{array}$ .

(c)

Interpretation Introduction

Interpretation:

• The reagents used to convert D into F have to be identified.
• The structure of E has to be found.

Concept Introduction:

 The given synthetic transformation scheme is shown here:

 For any given transformation, the following mandatory observations have to be made clear to predict the synthetic scheme:

• Observe whether there is any change in the carbon skeleton.
• Observe whether there is any change in the location of the functional group.
• Predict the synthetic scheme in such a way that these two observations have to be achieved within the minimum chemo selective steps.

Tosylation reaction:

The alcohol is treated with any tosyl chloride (methane sulfonyl chloride) which yields tosylated product this reaction is called as alkyl tosylate and which is shown below,

Wittig reaction:

It is the conversion of a ketone or an aldehyde into alkene using the ylide of phosphorus.

General Scheme

Gillman’s reagent:

It is the organometallic reagent that will be widely used to alkylate $\text{α,β}$ unsaturated double bonds.

It is represented as

$\begin{array}{l}{R}_{2}CuLi\\ R-\text{Alkyl}\text{or}\text{aryl}\end{array}$

Reduction with Lithium Aluminum hydride$(LAH)$:

Lithium Aluminum hydride reduces aldehydes, ketones and esters into alcohol.

Conversion of ketone into alcohol:

Conversion of aldehyde into alcohol:

Conversion of ester into alcohol:

Reaction of alcohol with acetic anhydride:

Alcohols react with acetic anhydride to give ester.

General scheme: