Chapter 21, Problem 21.44P

Give the structure corresponding to each name.

a. $2-\text{methyl}-3-\text{phenylbutanal}$

b. $3,3-\text{dimethylcycohexanecarbaldehyde}$

c. $3-\text{benzoylcyclopentanone}$

d. $2-\text{formylcyclopentanone}$

e. $\left(R\right)-3-\text{methylheptan}-2-\text{one}$

f. $m-\text{acetylbenzaldehyde}$

g. $2-\sec -\text{butylcyclopent}-3-\text{enone}$

h. $5,6-\text{dimethylcyclohex}-1-\text{enecarbaldehyde}$

Interpretation Introduction

(a)

Interpretation: The structure corresponding to $2-\text{methyl}-3-\text{phenylbutanal}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $2-\text{methyl}-3-\text{phenylbutanal}$ is shown below.

Figure 1

Explanation of Solution

The given name is $2-\text{methyl}-3-\text{phenylbutanal}$. The word root used in this is but. It means structure contains four 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 second carbon atom and one phenyl substituent is attached to the third carbon atom. The functional group present in the given compound is aldehyde $\left(\text{CHO}\right)$. The suffix used for aldehyde is –al.

Conclusion

The structure corresponding to $2-\text{methyl}-3-\text{phenylbutanal}$ is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation: The structure corresponding to $3,3-\text{dimethylcycohexanecarbaldehyde}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $3,3-\text{dimethylcycohexanecarbaldehyde}$ is shown below.

Figure 2

Explanation of Solution

The given name is $3,3-\text{dimethylcycohexanecarbaldehyde}$. The word root used in this is cyclohex. It means structure contains cyclic ring with six carbon atoms. The hydrocarbons that are attached to the longest chain are called substituents and they are written as prefix in alphabetical order. Two methyl substituents are attached to the third carbon atom. The functional group present in the given compound is aldehyde $\left(\text{CHO}\right)$. The suffix used for aldehyde is –al.

Conclusion

The structure corresponding to $3,3-\text{dimethylcycohexanecarbaldehyde}$ is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation: The structure corresponding to $3-\text{benzoylcyclopentanone}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $3-\text{benzoylcyclopentanone}$ is shown below.

Figure 3

Explanation of Solution

The given name is $3-\text{benzoylcyclopentanone}$. The word root used in this is cyclopent. It means structure contains cyclic ring of 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 benzoyl substituent is attached to the third carbon atom. The functional group present in the given compound is ketone $\left(-\text{CO}\right)$. The suffix used for ketone is –one.

Conclusion

The structure corresponding to $3-\text{benzoylcyclopentanone}$ is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation: The structure corresponding to $2-\text{formylcyclopentanone}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $2-\text{formylcyclopentanone}$ is shown below.

Figure 4

Explanation of Solution

The given name is $2-\text{formylcyclopentanone}$. The word root used in this is cyclopent. It means structure contains cyclic ring consisting of five carbon atoms. The hydrocarbons that are attached to the longest chain are called substituents and they are written as prefix in alphabetical order. The functional groups present in the given compound are aldehyde $\left(\text{CHO}\right)$ and ketone $\left(-\text{CO}\right)$. The suffix used for aldehyde is –al and for ketone is –one.

Conclusion

The structure corresponding to $2-\text{formylcyclopentanone}$ is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation: The structure corresponding to $\left(R\right)-3-\text{methylheptan}-2-\text{one}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $\left(R\right)-3-\text{methylheptan}-2-\text{one}$ is shown below.

Figure 5

Explanation of Solution

The given name is $\left(R\right)-3-\text{methylheptan}-2-\text{one}$. The word root used in this is hept. It means the structure contains seven 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 $\left(-\text{CO}\right)$. The suffix used for ketone is –one. The configuration of methyl group that is attached to the third carbon atom is $\left(R\right)$.

Conclusion

The structure corresponding to $\left(R\right)-3-\text{methylheptan}-2-\text{one}$ is shown in Figure 5.

Interpretation Introduction

(f)

Interpretation: The structure corresponding to $m-\text{acetylbenzaldehyde}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $m-\text{acetylbenzaldehyde}$ is shown below.

Figure 6

Explanation of Solution

The given name is $m-\text{acetylbenzaldehyde}$. In the given compound, one benzaldehyde group is present. One acetyl substituent is attached to the third carbon atom. The functional groups present in the given compound are aldehyde and ketone.

Conclusion

The structure corresponding to $m-\text{acetylbenzaldehyde}$ is shown in Figure 6.

Interpretation Introduction

(g)

Interpretation: The structure corresponding to $2-\sec -\text{butylcyclopent}-3-\text{enone}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $2-\sec -\text{butylcyclopent}-3-\text{enone}$ is shown below.

Figure 7

Explanation of Solution

The given name is $2-\sec -\text{butylcyclopent}-3-\text{enone}$. The word root used in this is cyclopent. It means structure contains cyclic ring consisting of 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 secondary butyl substituent is attached to the second carbon atom. The functional groups present in the given compound are aldehyde $\left(\text{CHO}\right)$ and ketone $\left(-\text{CO}\right)$. The suffix used for aldehyde is –al and for ketone is –one.

In the given compound, one benzaldehyde group is present. The functional group present in the given compound is ketone.

Conclusion

The structure corresponding to $2-\sec -\text{butylcyclopent}-3-\text{enone}$ is shown in Figure 7.

Interpretation Introduction

(h)

Interpretation: The structure corresponding to $5,6-\text{dimethylcyclohex}-1-\text{enecarbaldehyde}$ is to be drawn.

Concept introduction: The systematic naming of organic compound is given by IUPAC. The naming of organic compound is done such that the structure of organic compound is correctly interpreted from the name.

Rules for writing structural formula from IUPAC are:

• First identify the word root for the given compound.

• The suffix used in the compound like –ene.

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

Answer to Problem 21.44P

The structure corresponding to $5,6-\text{dimethylcyclohex}-1-\text{enecarbaldehyde}$ is shown below.

Figure 8

Explanation of Solution

The given name is $5,6-\text{dimethylcyclohex}-1-\text{enecarbaldehyde}$. The word root used in this is cyclohex. It means the structure contains cyclic ring consisting of six 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 fifth and sixth carbon atom. The functional groups present in the given compound is aldehyde $\left(\text{CHO}\right)$. The suffix used for aldehyde is –al.

Conclusion

The structure corresponding to $5,6-\text{dimethylcyclohex}-1-\text{enecarbaldehyde}$ is shown in Figure 8.