Chapter 14, Problem 14.7E

Interpretation Introduction

(a)

Interpretation:

The structural formula of methanal is to be drawn.

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 14.7E

The structural formula of methanal is,

Explanation of Solution

The given name is methanal. The functional group present in the given compound is aldehyde $\left(\text{CHO}\right)$. The suffix used for aldehyde is –al. The base name of the compound is methane. Therefore, the structure contains only one carbon atom to which aldehyde group is directly attached. Therefore, the structural formula of methanal is shown below.

Figure 1

Conclusion

The structural formula of methanal is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

The structural formula of $\text{3-ethyl-2-pentanone}$ is to be drawn.

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 14.7E

The structural formula of $\text{3-ethyl-2-pentanone}$ is,

Explanation of Solution

The given name is $\text{3-ethyl-2-pentanone}$. The root word used in this is pent. It means structure contains five carbon atoms. The hydrocarbons that are attached to the longest chain are called substituents and they are written as prefix in alphabetical order. One methyl substituent is attached to the third carbon atom. The functional group present in the given compound is ketone $\left(\text{R-CO-R}\right)$ because the suffix used for ketone is –one. It is present at second carbon atom. Therefore, the structure corresponding to $\text{3-ethyl-2-pentanone}$ is shown below.

Figure 2

Conclusion

The structural formula of $\text{3-ethyl-2-pentanone}$ is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation:

The structural formula of $\text{3-methylcyclohexanone}$ is to be drawn.

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 14.7E

The structural formula of $\text{3-methylcyclohexanone}$ is,

Explanation of Solution

The given name is $\text{3-methylcyclohexanone}$. The root word used in this is cyclohex. It means structure contains six carbon atoms in a ring. One methyl substituent is attached to the third carbon atom. The functional group present in the given compound is ketone $\left(\text{R-CO-R}\right)$ because the suffix used for ketone is –one. It is present at first carbon atom. Therefore, the structure corresponding to $\text{3-methylcyclohexanone}$ is shown below.

Figure 3

Conclusion

The structural formula of $\text{3-methylcyclohexanone}$ is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation:

The structural formula of $\text{2, 4, 6-trimethylheptanal}$ is to be drawn.

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 14.7E

The structural formula of $\text{2, 4, 6-trimethylheptanal}$ is,

Explanation of Solution

The given name is $\text{2, 4, 6-trimethylheptanal}$. The root word used in this is hept. It means structure contains seven carbon atoms. Three methyl substituents are attached to the second, fourth and sixth carbon atoms. The functional group present in the given compound is aldehyde $\left(\text{COH}\right)$ because the suffix used for aldehyde is –al. It is present at first carbon atom. Therefore, the structure corresponding to $\text{2, 4, 6-trimethylheptanal}$ is shown below.

Figure 4

Conclusion

The structural formula of $\text{2, 4, 6-trimethylheptanal}$ is shown in Figure 4.