Chapter 5, Problem 5.34EP

(a)

Interpretation Introduction

Interpretation:

IUPAC name for the fumaric acid has to be given.

Concept Introduction:

For naming a carboxylic acid in IUPAC nomenclature, the suffix “-oic” is added to the parent alkane name.

IUPAC rules for naming a carboxylic acid:

• The longest parent carbon chain is identified that includes the carboxyl group.
• The parent chain name is changed by replacing the suffix “-e” with “-oic acid”.
• Numbering is done in a way that the carboxyl group is designated as number 1.  This is not indicated in the part of the name because for aldehyde, the carboxyl carbon is always numbered 1.
• The identity and location of substituents if any has to be determined and this information has to be added in front of the IUPAC name.
• If the carboxyl functional group is attached to a ring of carbon atoms, the ring is named and “-carboxylic acid” is added as suffix.
• If the compound contains two carboxyl groups, then suffix “-dioic acid” is added after the parent alkane name.

Answer to Problem 5.34EP

IUPAC name of fumaric acid is trans-butenedioic acid.

Explanation of Solution

Structure of fumaric acid is,

The longest continuous carbon chain has to be found out with the carboxyl group in it.  In this it is a four carbon chain.  The structure contains a double bond in it.  The parent carbon chain is butene.  The given structure contains two carboxyl groups.  The carboxylic acid is named by adding suffix “-dioic acid”.  This gives the name of carboxylic acid as butenedioic acid.

Looking for substituents it is found that there are no substituents present in the carbon chain.  Stereochemistry is possible across the double bond.  As the two hydrogen atoms are on the opposite side of double bond, the configuration at the double bond is “trans”.  This has to be included in the name to get the IUPAC name.  IUPAC name of the fumaric acid is found as trans-butenedioic acid.

Conclusion

IUPAC name of fumaric acid is given.

(a)

Interpretation Introduction

Interpretation:

IUPAC name for the pyruvic acid has to be given.

Concept Introduction:

For naming a carboxylic acid in IUPAC nomenclature, the suffix “-oic” is added to the parent alkane name.

IUPAC rules for naming a carboxylic acid:

• The longest parent carbon chain is identified that includes the carboxyl group.
• The parent chain name is changed by replacing the suffix “-e” with “-oic acid”.
• Numbering is done in a way that the carboxyl group is designated as number 1.  This is not indicated in the part of the name because for aldehyde, the carboxyl carbon is always numbered 1.
• The identity and location of substituents if any has to be determined and this information has to be added in front of the IUPAC name.
• If the carboxyl functional group is attached to a ring of carbon atoms, the ring is named and “-carboxylic acid” is added as suffix.
• If the compound contains two carboxyl groups, then suffix “-dioic acid” is added after the parent alkane name.

Answer to Problem 5.34EP

IUPAC name of pyruvic acid is 2-oxopropanoic acid.

Explanation of Solution

Structure of pyruvic acid is,

The longest continuous carbon chain has to be found out with the carboxyl group in it.  In this it is a three carbon chain.  The parent alkane is propane.  The given structure contains a carboxyl group.  The carboxylic acid is named by replacing the suffix “-e” with suffix “-oic acid”.  This gives the name of carboxylic acid as propanoic acid.

Looking for substituents it is found that there is a keto group present on the second carbon atom.  Hence, the IUPAC name of the pyruvic acid is 2-oxopropanoic acid.

Conclusion

IUPAC name of pyruvic acid is given.

(c)

Interpretation Introduction

Interpretation:

IUPAC name for the malic acid has to be given.

Concept Introduction:

For naming a carboxylic acid in IUPAC nomenclature, the suffix “-oic” is added to the parent alkane name.

IUPAC rules for naming a carboxylic acid:

• The longest parent carbon chain is identified that includes the carboxyl group.
• The parent chain name is changed by replacing the suffix “-e” with “-oic acid”.
• Numbering is done in a way that the carboxyl group is designated as number 1.  This is not indicated in the part of the name because for aldehyde, the carboxyl carbon is always numbered 1.
• The identity and location of substituents if any has to be determined and this information has to be added in front of the IUPAC name.
• If the carboxyl functional group is attached to a ring of carbon atoms, the ring is named and “-carboxylic acid” is added as suffix.
• If the compound contains two carboxyl groups, then suffix “-dioic acid” is added after the parent alkane name.

Answer to Problem 5.34EP

IUPAC name of malic acid is 2-hydroxybutanedioic acid.

Explanation of Solution

Structure of malic acid is,

The longest continuous carbon chain has to be found out with the carboxyl group in it.  In this it is a four carbon chain.  The parent alkane is butane.  The given structure contains two carboxyl groups.  The carboxylic acid is named by adding the suffix “-dioic acid”.  This gives the name of carboxylic acid as butanedioic acid.

Looking for substituents it is found that there is a hydroxyl group at the second carbon atom.  Hence, the IUPAC name of the malic acid is 2-hydroxybutanoic acid.

Conclusion

IUPAC name of malic acid is given.

(d)

Interpretation Introduction

Interpretation:

IUPAC name for the tartaric acid has to be given.

Concept Introduction:

For naming a carboxylic acid in IUPAC nomenclature, the suffix “-oic” is added to the parent alkane name.

IUPAC rules for naming a carboxylic acid:

• The longest parent carbon chain is identified that includes the carboxyl group.
• The parent chain name is changed by replacing the suffix “-e” with “-oic acid”.
• Numbering is done in a way that the carboxyl group is designated as number 1.  This is not indicated in the part of the name because for aldehyde, the carboxyl carbon is always numbered 1.
• The identity and location of substituents if any has to be determined and this information has to be added in front of the IUPAC name.
• If the carboxyl functional group is attached to a ring of carbon atoms, the ring is named and “-carboxylic acid” is added as suffix.
• If the compound contains two carboxyl groups, then suffix “-dioic acid” is added after the parent alkane name.

Answer to Problem 5.34EP

IUPAC name of tartaric acid is 2,3-dihydroxybutanedioic acid.

Explanation of Solution

Structure of tartaric acid is,

The longest continuous carbon chain has to be found out with the carboxyl group in it.  In this it is a four carbon chain.  The parent alkane is butane.  The given structure contains two carboxyl groups.  The carboxylic acid is named by adding the suffix “-dioic acid”.  This gives the name of carboxylic acid as butanedioic acid.

Looking for substituents it is found that there are two hydroxyl groups present, each at the second carbon atom and third carbon atom.  Hence, the IUPAC name of the tartaric acid is 2,3-dihydroxybutanoic acid.

Conclusion

IUPAC name of tartaric acid is given.