Chapter 21, Problem 78PP

(a)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

Carbonyl compound when treated with LDA undergoes deprotonation at the $\alpha$ carbon to form enolate.  The enolate formed is resonance stabilized as the negative charge will be spread over other atoms too.  The resonance stabilized intermediate undergoes reaction with other molecule of carbonyl (same or different) to form the respective products.  If LDA is used as a base the less substituted $\alpha$ carbon is deprotonated due to steric hindrance.

• Deprotonation of $\alpha$ carbon to form enolate
• Nucleophilic attack of enolate
• S_N2 reaction with alkyl halide

(b)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

When a ketone is deprotonated to form a resonance stabilized enolate ion (Michael donor) which acts as a nucleophile for 1,4-conjugate addition to $\alpha \text{, }\beta$-unsaturated compound (Michael acceptor) is known as Michael reaction.  Michael reaction is thermodynamically controlled.  A general scheme is shown below,

(c)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

When a ketone is deprotonated to form a resonance stabilized enolate ion (Michael donor) which acts as a nucleophile for 1,4-conjugate addition to $\alpha \text{, }\beta$-unsaturated compound (Michael acceptor) is known as Michael reaction.  Michael reaction is thermodynamically controlled.  A general scheme is shown below,

(d)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

Retrosynthetic approach is a method used to find the starting material from the structure of product by breaking it into simpler fragments and deducing a route for synthesis of the simpler fragments step by step to give the required product.

• Change in carbon-carbon framework
• Position of functional group.

(e)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

Retrosynthetic approach is a method used to find the starting material from the structure of product by breaking it into simpler fragments and deducing a route for synthesis of the simpler fragments step by step to give the required product.

• Change in carbon-carbon framework
• Position of functional group.

(f)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

Retrosynthetic approach is a method used to find the starting material from the structure of product by breaking it into simpler fragments and deducing a route for synthesis of the simpler fragments step by step to give the required product.

• Change in carbon-carbon framework
• Position of functional group.

(g)

Interpretation Introduction

Interpretation:

Reagents used for the transformation of cyclohexanone into the products given need to be identified.

Concept introduction:

Retrosynthetic approach is a method used to find the starting material from the structure of product by breaking it into simpler fragments and deducing a route for synthesis of the simpler fragments step by step to give the required product.

• Change in carbon-carbon framework
• Position of functional group.