Chapter 23.3, Problem 21LC

(a)

Interpretation Introduction

Interpretation: To write the IUPAC names for the given carbonyl compounds.

Concept Introduction: Carbonyl group is the combination of carbon and oxygen double bound together. If the general formula of a carbonyl compound is $\text{RCHO}$ , then it is called an aldehyde and if it is ${\text{ROR}}^{\text{'}}$ , then it is called ketone. This difference between the aldehyde and the ketone is due to the position of the carbonyl group in the compound.

Answer to Problem 21LC

  

The IUPAC name of the given compound is Propan-1-al.

Explanation of Solution

In the given compound the longest carbon chain contains three carbons and the functional group present is $\text{-CHO}$ that is attached to the alkyl chain, which represents the aldehyde group. Therefore, it is named Propan-1-al.

(b)

Interpretation Introduction

Interpretation: To write the IUPAC names for the given carbonyl compounds.

Concept Introduction: Carbonyl group is the combination of carbon and oxygen double bound together. If the general formula of a carbonyl compound is $\text{RCHO}$ , then it is called an aldehyde and if it is ${\text{ROR}}^{\text{'}}$ , then it is called a ketone. This difference between the aldehyde and the ketone is due to the position of the carbonyl group in the compound.

Answer to Problem 21LC

  

The IUPAC name of the given compound is Hexan-3-one.

Explanation of Solution

The given compound contains the longest carbon chain with six carbons and the carbonyl group is present between the carbon chain. This shows that the carbonyl group that is present is a ketone and the carbonyl group is considered the third carbon. Therefore, the name is given as Hexan-3-one.

(c)

Interpretation Introduction

Interpretation: To write the IUPAC names for the given carbonyl compounds.

Concept Introduction: The nomenclature of carboxylic acids includes the selection of the longest carbon chain. The functional group should be numbered in such a way that it gets the lowest number. The naming will include the substituent followed by the longest chain containing the functional group with the suffix “-oic acid”.

Answer to Problem 21LC

  

The given IUPAC name is Pentan-1-oic acid.

Explanation of Solution

In the given compound the longest carbon chain contains five carbons. The functional group present in this case is carboxylic acid. Therefore, the name of the compound is given as Pentan-1-oic acid.