Chapter 20, Problem 145CP

Interpretation Introduction

(a)

Interpretation:

Name of the given organic compound should be determined.

Concept Introduction:

The group that contains carboxyl group which is attached to at least one hydrogen is said to be an aldehyde group, general representation of an aldehyde group is RCH=O or RCHO. Whereas the group that contains carboxyl group which is attached to two carbon atoms is said to be a ketone group, general representation of a ketone group is RCOR’.

In order to give the name to the aldehyde group, the following steps are followed:

1. The parent (longest) alkane chain is identified.

2. The ending of the parent chain from alkane (-e) is changed to -al for an aldehyde group. The carbonyl group of an aldehyde appear at the end of the carbon chain so, the numbering start with carbon having aldehyde group.

3. Name should be written in alphabetical order and other substituents are shown by the number.

For number of carbons atoms chain, the prefix is given as:

Carbon-1meth

Carbon-2eth

Carbon-3prop

Carbon-4but

Carbon-5pent

Carbon-6hex

Carbon-7hept

Carbon-8oct

Carbon-9non

Carbon-10dec.

Answer to Problem 145CP

Name of the given compound is:

Heptanal.

Explanation of Solution

The given structure is:

The parent chain in the given structure is heptane. Numbering is done in such a way that carbonyl carbon gets number 1.

So, the name will be: heptanal.

Interpretation Introduction

(b)

Interpretation:

Name of the given organic compound should be determined.

Concept Introduction:

The group that contains carboxyl group which is attached to at least one hydrogen is said to be an aldehyde group, general representation of an aldehyde group is RCH=O or RCHO. Whereas the group that contains carboxyl group which is attached to two carbon atoms is said to be a ketone group, general representation of a ketone group is RCOR’.

In order to give the name to the aldehyde group, the following steps are followed:

1. The parent (longest) alkane chain is identified.

2. The ending of the parent chain from alkane (-e) is changed to -al for an aldehyde group. The carbonyl group of an aldehyde appear at the end of the carbon chain so, the numbering start with carbon having aldehyde group.

3. Name should be written in alphabetical order and other substituents are shown by the number.

For number of carbons atoms chain, the prefix is given as:

Carbon-1meth

Carbon-2eth

Carbon-3prop

Carbon-4but

Carbon-5pent

Carbon-6hex

Carbon-7hept

Carbon-8oct

Carbon-9non

Carbon-10dec.

Answer to Problem 145CP

Name of the given compound is:

3-ethyl-5-methylhexanal.

Explanation of Solution

The given structure is:

The parent chain in the given structure is hexane. Numbering is done in such a way that carbonyl carbon gets number 1.

The substituent on 3 position is ethyl and on 5 position is methyl.

So, the name will be: 3-ethyl-5-methylhexanal.

Interpretation Introduction

(c)

Interpretation:

Name of the given organic compound should be determined.

Concept Introduction:

The group that contains carboxyl group which is attached to at least one hydrogen is said to be an aldehyde group, general representation of an aldehyde group is RCH=O or RCHO. Whereas the group that contains carboxyl group which is attached to two carbon atoms is said to be a ketone group, general representation of a ketone group is RCOR’.

In order to give the name to the ketone group, the following steps are followed:

1. The parent (longest) alkane chain is identified.

2. The ending of the parent chain from alkane (-e) is changed to -one for a ketone group.

3. The numbering is of the chain is done in such a way that carbonyl carbon gets the smaller number.

4. Name should be written in alphabetical order and other substituents are shown by the number.

For number of carbons atoms chain, the prefix is given as:

Carbon-1meth

Carbon-2eth

Carbon-3prop

Carbon-4but

Carbon-5pent

Carbon-6hex

Carbon-7hept

Carbon-8oct

Carbon-9non

Carbon-10dec.

Answer to Problem 145CP

Name of the given compound is:

Hexan-3-one.

Explanation of Solution

The given structure is:

The parent chain in the given structure is hexane. Numbering is done in such a way that carbonyl carbon gets lower number that is 3.

So, the name will be: Hexan-3-one.

Interpretation Introduction

(d)

Interpretation:

Name of the given organic compound should be determined.

Concept Introduction:

The group that contains carboxyl group which is attached to at least one hydrogen is said to be an aldehyde group, general representation of an aldehyde group is RCH=O or RCHO. Whereas the group that contains carboxyl group which is attached to two carbon atoms is said to be a ketone group, general representation of a ketone group is RCOR’.

In order to give the name to the ketone group, the following steps are followed:

1. The parent (longest) alkane chain is identified.

2. The ending of the parent chain from alkane (-e) is changed to -one for a ketone group.

3. The numbering is of the chain is done in such a way that carbonyl carbon gets the smaller number.

4. Name should be written in alphabetical order and other substituents are shown by the number.

For number of carbons atoms chain, the prefix is given as:

Carbon-1meth

Carbon-2eth

Carbon-3prop

Carbon-4but

Carbon-5pent

Carbon-6hex

Carbon-7hept

Carbon-8oct

Carbon-9non

Carbon-10dec.

Answer to Problem 145CP

Name of the given compound is:

4, 5-dimethylhexan-3-one.

Explanation of Solution

The given structure is:

The parent chain in the given structure is hexane. Numbering is done in such a way that carbonyl carbon gets lower number that is 3.

The substituent on 4 and 5 position is methyl.

So, the name will be: 4, 5-dimethylhexan-3-one.

Interpretation Introduction

(e)

Interpretation:

Name of the given organic compound should be determined.

Concept Introduction:

An organic compound in which carboxy functional group that is -COOH is bonded to the carbon atom is said to be a carboxylic acid. The general formula for carboxylic acid is RCOOH or RCO₂ H.

In order to give the name to the carboxylic acid group, the following steps are followed:

1. The parent (longest) alkane chain is identified.

2. The ending of the parent chain from alkane (-e) is changed to -oic acid for a carboxylic acid group.

3. The numbering is of the chain is done in such a way that carbonyl carbon gets the smaller number.

4. Name should be written in alphabetical order and other substituents are shown by the number.

For number of carbons atoms chain, the prefix is given as:

Carbon-1meth

Carbon-2eth

Carbon-3prop

Carbon-4but

Carbon-5pent

Carbon-6hex

Carbon-7hept

Carbon-8oct

Carbon-9non

Carbon-10dec.

Answer to Problem 145CP

Name of the given compound is:

3, 4-dimethylhexanoic acid.

Explanation of Solution

The given structure is:

The parent chain in the given structure is hexane. Numbering is done in such a way that carboxyl group gets number 1.

The substituent on 3 and 4 position is methyl.

So, the name will be: 3, 4-dimethylhexanoic acid.