Chapter 14, Problem 14.5E

Interpretation Introduction

(a)

Interpretation:

The IUPAC name of the given compound is to be assigned.

Concept introduction:

The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done in such a way that the structure of organic compound is correctly interpreted from the name.

Rules for writing the structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ane, ene, yne, ol, al and so on.

• Identify the position, location, and number of the substituent bonded to the carbon chain.

Aldehydes and ketones contain carbonyl functional group in their parent chain and are named by adding suffix –al and –one to the name of the parent alkane.

Answer to Problem 14.5E

The IUPAC name of the given aldehyde is ethanal.

Explanation of Solution

The given compound is shown below.

Figure 1

The given compound is aldehyde. The first step in the naming of aldehyde is finding of longest parent chain that contains a carbonyl group. The second step is changing of -e ending of the parent alkane to the suffix -al. The third step is numbering of chain to give the least number to carbonyl carbon, and using the general rules of nomenclature.

The given structure shows the presence of two $\text{C's}$ in the chain. Thus, its corresponding alkane is ethane. On this chain, the $\text{C}=\text{O}$ group is substituted at $\text{C1}$. Therefore, the IUPAC name of this aldehyde is ethanal.

Conclusion

The given aldehyde is ethanal.

Interpretation Introduction

(b)

Interpretation:

The IUPAC name of the given compound is to be assigned.

Concept introduction:

The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done in such a way that the structure of organic compound is correctly interpreted from the name.

Rules for writing the structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ane, ene, yne, ol, al and so on.

• Identify the position, location, and number of the substituent bonded to the carbon chain.

Aldehydes and ketones contain carbonyl functional group in their parent chain and are named by adding suffix –al and –one to the name of the parent alkane.

Answer to Problem 14.5E

The IUPAC name of the given aldehyde is $\text{2, 4-dimethylpentanal}$.

Explanation of Solution

The given compound is shown below.

Figure 2

The given compound is aldehyde. The first step in the naming of aldehyde is finding of longest parent chain that contains a carbonyl group. The second step is changing of -e ending of the parent alkane to the suffix -al. The third step is numbering of chain to give the least number to carbonyl carbon, and using the general rules of nomenclature.

The given structure shows the presence of five $\text{C's}$ in the longest chain. Thus, its corresponding alkane is pentane. On this chain, the $\text{C}=\text{O}$ group is substituted at $\text{C1}$. The two methyl groups are substituted at $\text{C2}$ and $\text{C4}$. Therefore, the IUPAC name of this aldehyde is $\text{2, 4-dimethylpentanal}$.

Conclusion

The given aldehyde is $\text{2, 4-dimethylpentanal}$.

Interpretation Introduction

(c)

Interpretation:

The IUPAC name of the given compound is to be assigned.

Concept introduction:

The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done in such a way that the structure of organic compound is correctly interpreted from the name.

Rules for writing the structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ane, ene, yne, ol, al and so on.

• Identify the position, location, and number of the substituent bonded to the carbon chain.

Aldehydes and ketones contain carbonyl functional group in their parent chain and are named by adding suffix –al and –one to the name of the parent alkane.

Answer to Problem 14.5E

The IUPAC name of the given ketone is $\text{4-methyl-2-pentanone}$.

Explanation of Solution

The given compound is shown below.

Figure 3

The given compound is ketone. The first step in the naming of ketone is finding of longest parent chain that contains a carbonyl group. The second step is changing of -e ending of the parent alkane to the suffix -one. The third step is numbering of chain to give the least number to carbonyl carbon, and using the general rules of nomenclature.

The given structure shows the presence of five $\text{C's}$ in the longest chain. Thus, its corresponding alkane is pentane. On this chain, the $\text{C}=\text{O}$ group is substituted at $\text{C2}$. The methyl group is substituted at $\text{C4}$. Therefore, the IUPAC name of this ketone is $\text{4-methyl-2-pentanone}$.

Conclusion

The given ketone is $\text{4-methyl-2-pentanone}$.

Interpretation Introduction

(d)

Interpretation:

The IUPAC name of the given compound is to be assigned.

Concept introduction:

The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done in such a way that the structure of organic compound is correctly interpreted from the name.

Rules for writing the structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ane, ene, yne, ol, al and so on.

• Identify the position, location, and number of the substituent bonded to the carbon chain.

Aldehydes and ketones contain carbonyl functional group in their parent chain and are named by adding suffix –al and –one to the name of the parent alkane.

Answer to Problem 14.5E

The IUPAC name of the given aldehyde is $\text{3-phenylpentanal}$.

Explanation of Solution

The given compound is shown below.

Figure 4

The given compound is aldehyde. The first step in the naming of aldehyde is finding of longest parent chain that contains a carbonyl group. The second step is changing of -e ending of the parent alkane to the suffix -al. The third step is numbering of chain to give the least number to carbonyl carbon, and using the general rules of nomenclature.

The given structure shows the presence of five $\text{C's}$ in the longest chain. Thus, its corresponding alkane is pentane. On this chain, the $\text{C}=\text{O}$ group is substituted at $\text{C1}$. The phenyl group is substituted at $\text{C3}$. Therefore, the IUPAC name of this aldehyde is $\text{3-phenylpentanal}$.

Conclusion

The given aldehyde is $\text{3-phenylpentanal}$.

Interpretation Introduction

(e)

Interpretation:

The IUPAC name of the given compound is to be assigned.

Concept introduction:

The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done in such a way that the structure of organic compound is correctly interpreted from the name.

Rules for writing the structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ane, ene, yne, ol, al and so on.

• Identify the position, location, and number of the substituent bonded to the carbon chain.

Aldehydes and ketones contain carbonyl functional group in their parent chain and are named by adding suffix –al and –one to the name of the parent alkane.

Answer to Problem 14.5E

The IUPAC name of the given cyclic ketone is $\text{2-methylcyclopropanone}$.

Explanation of Solution

The given compound is shown below.

Figure 5

The given compound is cyclic ketone. The first step in the naming of ketone is finding of longest parent chain that contains a carbonyl group. The second step is changing of -e ending of the parent alkane to the suffix -one. The third step is numbering of chain to give the least number to carbonyl carbon, and using the general rules of nomenclature.

The given structure shows the presence of three $\text{C's}$ in the ring. Thus, its corresponding parent name is cyclopropane. On this ring, the $\text{C}=\text{O}$ group is substituted at $\text{C1}$. The methyl group is substituted at $\text{C2}$. Therefore, the IUPAC name of this cyclic ketone is $\text{2-methylcyclopropanone}$.

Conclusion

The given cyclic ketone is $\text{2-methylcyclopropanone}$.