Chapter 12, Problem 46P

(a)

Interpretation Introduction

Interpretation: The products of the given reaction have to be found.

Concept Introduction:

Grignard reaction with ketone:

Grignard regent reacts with ketone followed by acidic work up to form secondary or tertiary alcohol.

General scheme:

  

(b)

Interpretation Introduction

Interpretation: The products of the given reaction have to be found.

Concept Introduction:

Hemiketals:

Hemiaketals are compounds with the functional group $\text{C}\left(\text{OH}\right)\left(\text{OR}\right)$. These compounds will be formed as intermediates in the formation of Ketals from ketones which is shown in the following general scheme:

General scheme:

  

(c)

Interpretation Introduction

Interpretation: The products of the given reaction have to be found.

Concept Introduction:

Major product in the reaction of $\alpha ,\beta -$ unsaturated carbonyl compounds with weak bases:

$\text{α,β-}$ Unsaturated carbonyl compounds on reaction with weak bases gives conjugate addition products as the major products as shown in the following general scheme:

General scheme:

It can be observed that the conjugate addition product has been formed by the addition of basic anion to the beta-carbon atom and that of hydrogen atom to the alpha-carbon carbon atom.

The examples for the weak bases are:

$\begin{array}{l}•\text{HBr}\\ •{\text{CH}}_{\text{3}}\text{SH}\\ •{\text{CH}}_{\text{3}}\text{OH}\\ •{\text{NH}}_3\end{array}$

(d)

Interpretation Introduction

Interpretation: The products of the given reaction have to be found.

Concept Introduction:

Major product in the reaction of $\alpha ,\beta -$ unsaturated carbonyl compounds with weak bases:

$\text{α,β-}$ Unsaturated carbonyl compounds on reaction with weak bases gives conjugate addition products as the major products as shown in the following general scheme:

General scheme:

It can be observed that the conjugate addition product has been formed by the addition of basic anion to the beta-carbon atom and that of hydrogen atom to the alpha-carbon carbon atom.

The examples for the weak bases are:

$\begin{array}{l}•\text{HBr}\\ •{\text{CH}}_{\text{3}}\text{SH}\\ •{\text{CH}}_{\text{3}}\text{OH}\\ •{\text{NH}}_3\end{array}$

Major product in the reaction of $\alpha ,\beta -$ unsaturated carbonyl compounds with strong bases:

$\text{α,β-}$ Unsaturated carbonyl compounds on reaction with strong bases gives direct addition products as the major products as shown in the following general scheme:

General scheme:

It can be observed that the direct addition product has been formed from the direct reaction of the strong base with the carbonyl functional group of the $\text{α,β-}$ unsaturated carbonyl compounds.

The examples for the strong bases are:

$\begin{array}{l}•{}^{-}{\text{CH}}_3{\text{Mg}}^{2+}{\text{Br}}^{-}\Rightarrow \text{Gignard}\text{reagent}\\ •{\text{NaBH}}_4\Rightarrow {\text{H}}^{\text{-}}\text{hydride}\text{donor}\end{array}$

Aminolysis reaction:

• The aminolysis reaction is just like hydrolysis in which one component gets converted into two components using a molecule of amine like using a molecule of water in hydrolysis.
• In the aminolysis of ester, one ester component reacts with a molecule of amine and will be converted into two components such as an amide and an alcohol which has been shown in the following general scheme: