Chapter 21.1, Problem 6CC

(a)

Interpretation Introduction

Interpretation:

• For the given ketone, the formation of enolate using sodium ethoxide has to be drawn.
• Whether equilibrium exits or not between the enolate and the given ketone, has to be predicted.

Concept Introduction:

Enolate formation:

When ketones are treated with a strong base, the $\text{α-position}$ of the ketone will be deprotonated to give a resonance-stabilized intermediate called an enolate.

Example:

Equilibrium with Enolates:

Diketones are highly acidic. So there is no need of using a strong base like $\text{LDA}$. It is will be well sufficient to use comparatively less bases such as ethoxide or alkoxide with which there will be irreversible formation of the enolate. But the ketones other than diketones are least acidic. So the attack of the bases such as ethoxide or alkoxide will establish equilibrium between the ketones and the enolate. In that equilibrium, the ketones will be more favoured than the enolate.

(b)

Interpretation Introduction

Interpretation:

• For the given ketone, the formation of enolate using sodium ethoxide has to be drawn.
• Whether equilibrium exits or not between the enolate and the given ketone, has to be predicted.

Concept Introduction:

Enolate formation:

When ketones are treated with a strong base, the $\text{α-position}$ of the ketone will be deprotonated to give a resonance-stabilized intermediate called an enolate.

Example:

Equilibrium with Enolates:

Diketones are highly acidic. So there is no need of using a strong base like $\text{LDA}$. It is will be well sufficient to use comparatively less bases such as ethoxide or alkoxide with which there will be irreversible formation of the enolate. But the ketones other than diketones are least acidic. So the attack of the bases such as ethoxide or alkoxide will establish equilibrium between the ketones and the enolate. In that equilibrium, the ketones will be more favoured than the enolate.

(c)

Interpretation Introduction

Interpretation:

• For the given ketone, the formation of enolate using sodium ethoxide has to be drawn.
• Whether equilibrium exits or not between the enolate and the given ketone, has to be predicted.

Concept Introduction:

Enolate formation:

When ketones are treated with a strong base, the $\text{α-position}$ of the ketone will be deprotonated to give a resonance-stabilized intermediate called an enolate.

Example:

Equilibrium with Enolates:

Diketones are highly acidic. So there is no need of using a strong base like $\text{LDA}$. It is will be well sufficient to use comparatively less bases such as ethoxide or alkoxide with which there will be irreversible formation of the enolate. But the ketones other than diketones are least acidic. So the attack of the bases such as ethoxide or alkoxide will establish equilibrium between the ketones and the enolate. In that equilibrium, the ketones will be more favoured than the enolate.

(d)

Interpretation Introduction

Interpretation:

• For the given ketone, the formation of enolate using sodium ethoxide has to be drawn.
• Whether equilibrium exits or not between the enolate and the given ketone, has to be predicted.

Concept Introduction:

Enolate formation:

When ketones are treated with a strong base, the $\text{α-position}$ of the ketone will be deprotonated to give a resonance-stabilized intermediate called an enolate.

Example:

Equilibrium with Enolates:

Diketones are highly acidic. So there is no need of using a strong base like $\text{LDA}$. It is will be well sufficient to use comparatively less bases such as ethoxide or alkoxide with which there will be irreversible formation of the enolate. But the ketones other than diketones are least acidic. So the attack of the bases such as ethoxide or alkoxide will establish equilibrium between the ketones and the enolate.  In that equilibrium, the ketones will be more favoured than the enolate.