Chapter 22, Problem 45A

(a)

Interpretation Introduction

Interpretation- To name the given compound.

Concept Introduction- IUPAC nomenclature follows some rule for naming the compounds as:

1. Identify the longest parent chain.
2. Identify the substituents.
3. Number each carbon in the parent chain in such a way that substituents get the lowest numbers.
4. If the substituents are more than one, prefixes like di, tri, tetra etc are used.
5. The name of compound starts with substituents with their position in parent chain. They are written in alphabetical order.
6. Number and name are separated by dash while number are separated by commas.
7. The chain name is based on the number of carbon atom present like meth, eth, prop, but, pent, hex, hept, oct, non, dec,…
8. Suffix “ane” is used for alkane parent chain and “yl is used for substituents.

Answer to Problem 45A

The name of compound is $2-methylbutane$

Explanation of Solution

  

The compound has the longest parent chain with four carbon atoms. Hence the parent name chain will be ‘but’ with suffix “ane”.

Substituent has one carbon atom, and it is present on second carbon atom of the parent chain. Hence the name will be $2-methyl$ ,

Therefore, the name of compound is $2-methylbutane$

Conclusion

Therefore, the name of compound is $2-methylbutane$

(b)

Interpretation Introduction

Interpretation- To name the given compound.

Introduction- IUPAC nomenclature follows some rule for naming the compounds as:

1. Identify the longest parent chain.
2. Identify the substituents.
3. Number each carbon in the parent chain in such a way that substituents get the lowest numbers.
4. If the substituents are more than one, prefixes like di, tri, tetra etc are used.
5. The name of compound starts with substituents with their position in parent chain. They are written in alphabetical order.
6. Number and name are separated by dash while number are separated by commas.
7. The chain name is based on the number of carbon atom present like meth, eth, prop, but, pent, hex, hept, oct, non, dec, …

Suffix “ane” is used for alkane parent chain and “yl is used for substituents

Answer to Problem 45A

The name of compound is $2,3-dimethylbutane$

Explanation of Solution

  

The compound has the longest parent chain with four carbon atoms. Hence the parent name chain will be “but” with suffix “ane”.

There are two methyl substituents present on second and third carbon atom of parent chain. Prefix “di” will be used. Hence the name will be $2,3-dimethyl$

Therefore, the name of compound is $2,3-dimethylbutane$

Conclusion

Therefore, the name of compound is $2,3-dimethylbutane$

(c)

Interpretation Introduction

Interpretation- To name the given compound.

Introduction- IUPAC nomenclature follows some rule for naming the compounds as:

1. Identify the longest parent chain.
2. Identify the substituents.
3. Number each carbon in the parent chain in such a way that substituents get the lowest numbers.
4. If the substituents are more than one, prefixes like di, tri, tetra etc are used.
5. The name of compound starts with substituents with their position in parent chain. They are written in alphabetical order.
6. Number and name are separated by dash while number are separated by commas.
7. The chain name is based on the number of carbon atom present like meth, eth, prop, but, pent, hex, hept, oct, non, dec,…
8. Suffix “ane” is used for alkane parent chain and “yl is used for substituents.

Answer to Problem 45A

The name of compound is $3-methylhexane$

Explanation of Solution

  

The compound has the longest parent chain with six carbon atoms. Hence the parent name chain will be hex with suffix “ane”.

Substituent has one carbon atom, and it is present on third carbon atom of the parent chain. Hence the name will be $3-methyl$ ,

Therefore, the name of compound is $3-methylhexane$

Conclusion

Therefore, the name of compound is $3-methylhexane$