Chapter 12, Problem 29P

(a)

Interpretation Introduction

Interpretation:

The product of the given reaction has to be identified.

Concept Introduction:

Acetals:

Acetals are used to protect the ketone and aldehyde (carbonyl group).

In this reaction acetone is protected as acetal by using ethylene glycol. Acetals are less stable compound.

In acidic condition, an aldehyde or a ketone reacts with two molecules of alcohol or a molecule of diol to form acetal or cyclic acetal respectively.

General scheme:

(b)

Interpretation Introduction

Interpretation:

The product of the given reaction has to be identified.

Concept Introduction:

Imine formation:

Aldehyde or ketone reacts with a primary amine and forms imine in mildly acidic conditions.

Example for the formation of imine is shown here:

  

• Imines contain $C=N$ .
• Imines are also called as Schiff bases, named after Hugo Schiff who described their formation.

(c)

Interpretation Introduction

Interpretation:

The product of the given reaction has to be identified.

Concept Introduction:

 ${\text{NaBH}}_{\text{4}}$ - Sodium borohydride is a reducing agent.

 It reduces aldehydes, ketones and carboxylic acids into alcohols.

(d)

Interpretation Introduction

Interpretation:

The product of the given reaction has to be identified.

Concept Introduction:

Carbonyl compounds on treatment with sodium cyanide give cyanohydrin which on further dilution with acid result in carboxylic acid.