Chapter 11, Problem 11D.13E

(a)

Interpretation Introduction

Interpretation:

The compound ${\text{CH}}_{\text{3}}\text{CHO}$ has to be identified as aldehyde or ketone and the systematic name has to be provided.

Concept Introduction:

Aldehydes:

Aldehydes and ketones comprises of a carbonyl group, a functional group with a carbon-oxygen double bond.

In aldehyde, the carbonyl group is bonded to atleast one hydrogen atom.

The general formula for aldehyde is $\text{R-CHO}\text{.}$

IUPAC nomenclature for naming aldehydes:

• The parent compound; that is the longest continuous carbon chain containing the carbonyl group has to be determined.
• Replace the final –e of the parent alkane with –al.
• The chain beginning with the carbonyl carbon is named as carbon $\text{-1}\text{.}$
• All the substituents are named and numbered.
• No number is used for the position of carbonyl group because it is always at the end of the parent chain.  Therefore it must be carbon $\text{-1}\text{.}$

(b)

Interpretation Introduction

Interpretation:

The compound ${\text{CH}}_{\text{3}}{\text{COCH}}_3$ has to be identified as aldehyde or ketone and the systematic name has to be provided.

Concept Introduction:

Ketones:

Aldehydes and ketones comprises of a carbonyl group, a functional group with a carbon-oxygen double bond.

In ketones, the carbonyl group is bonded to two carbon atoms.

The compound $\text{R-CO-R}$ is identified as ketone.

IUPAC nomenclature of naming ketones:

• The parent compound that is the longest carbon chain containing the carbonyl group has to be determined.
• Replace the –e ending of the parent alkane with –one suffix of the ketone family.
• The carbon atom has to be numbered.  The carbonyl carbon takes the lowest possible number.

(c)

Interpretation Introduction

Interpretation:

The compound ${\left({\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\right)}_{\text{2}}\text{CO}$ has to be identified as aldehyde or ketone and the systematic name has to be provided.

Concept Introduction:

Refer to part (b).