1. 14 Carboxylic Acids and Carboxylic Acid Derivatives
ORGANIC CHEMISTRY 14
Carboxylic Acids and Carboxylic Acid Derivatives
General, Organic, and Biochemistry 9th Edition
Katherine J. Denniston
Joseph J. Topping
Danaè R. Quirk Dorr
Robert L. Caret
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2. Functional Group Formulas
Ar= Aromatic hydrocarbon R = Aliphatic hydrocarbon

3. Structure 14.1 Carboxylic Acids
Carboxylic acid groups consist of two very polar functional groups
Carbonyl group
Hydroxyl group
Carboxylic acid groups are very polar 1
Carboxylic acid Ester – Carboxylic Acid Derivative
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4. Physical Properties 14.1 Carboxylic Acids
Low molar mass carboxylic acids
Sharp, sour taste
Unpleasant aromas
High molar mass carboxylic acids
Fatty acids important in biochemistry
Low molar mass carboxylic acids are water soluble due to hydrogen bonding with:
Water
Each other
14.1 Carboxylic Acids
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5. Boiling Points 14.1 Carboxylic Acids
Due to carboxylic acids forming intermolecular hydrogen bonds, boiling points are at higher temperatures than those of any other functional group studied
14.1 Carboxylic Acids

6. Nomenclature 14.1 Carboxylic Acids2
Determine the parent compound: 4C – butane
Number the chain so that the carboxyl carbon is carbon 1: from right to left
Replace the –e ending with –oic acid
Butanoic acid
If two carboxyl groups are present use –dioic acid
Complete naming as usual – bromine on C-3
14.1 Carboxylic Acids 4 3 2 1

7. Carboxylic Acid Naming Examples
14.1 Carboxylic Acids

8. Common Names 14.1 Carboxylic Acids Use Latin or Greek prefixes
Suffix is –ic acid
Greek letters indicate the position of the substituents
14.1 Carboxylic Acids

9. Names and Structures of Some Common Carboxylic Acids

10. Benzoic Acid Derivatives
14.1 Carboxylic Acids

11. Carboxylic Acids with a Phenyl Substituent
The phenyl group is benzene with one hydrogen removed:
14.1 Carboxylic Acids

12. Common Dicarboxylic Acids3
14.1 Carboxylic Acids

13. Some Important Carboxylic Acids3
More complex carboxylic acids are found in a variety of foods
Citric Acid is found in citrus fruits
Bacteria in mild produce lactic acid as a product of fermentation of sugars
Tartaric acid is used in baking powder because it will react with carbonates in the dough
Malic acid gives the sour taste to green apples
Fatty acids are long chain carboxylic acids found in plant and animal sources
14.1 Carboxylic Acids

14. Carboxylic Acids Found in Food3
14.1 Carboxylic Acids

15. Reactions Involving Carboxylic Acids4
Carboxylic acids are prepared by oxidation of primary alcohols and aldehydes
14.1 Carboxylic Acids

16. Carboxylate Anion Formation5
Carboxylic acids behave as acids because when they are dissolved in water they will deprotonate to form a carboxylate ion and the hydronium ion
Carboxylic acids are weak acids with dissociations of less than 5%
14.1 Carboxylic Acids
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17. Neutralization Reactions
Carboxylic acids DO react with strong bases to form carboxylate salts
A process of neutralization
Acid protons are removed by the –OH- to form H2O and carboxylate ion
Equilibrium shifts to the right with removal of H+
14.1 Carboxylic Acids

18. Acid-Base Reactions 14.1 Carboxylic Acids
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19. Salts of Carboxylic Acids
Nomenclature
First add the cation’s name
Sodium
Then drop the –oic acid and add –ate
Sodium benzoate
Uses of carboxylic acids
Soaps like sodium stearate
Preservatives
Anti-fungal medicines
Used to control food pH
14.1 Carboxylic Acids

20. Esterification 14.1 Carboxylic Acids 6
Carboxylic acids react with alcohols to form:
Esters
Water
14.1 Carboxylic Acids
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21. 14.2 Esters 7 Structure and physical properties
Esters are mildly polar, somewhat water soluble
Frequently found in natural foodstuffs
Many have pleasant aromas
Isoamyl acetate = banana oil
3-methylbutyl ethanoate
Ethyl butanoate = pineapple aroma
Ethyl butanoate
Isobutyl formate = raspberry aroma
Isobutyl methanoate
Boil at approximately the same temperature as carbonyls with comparable molecular weight

22. Ester IUPAC Nomenclature8
Form from the reaction of a carboxylic acid with an alcohol, which is reflected in the naming
Use the alkyl group as the first name
(Alcohol part of the ester)
Base the name for the acid part of the structure from the longest chain ending in the C=O
(Carboxylic acid part of the ester)
Change the –oic acid of the acid name to –oate
14.2 Esters
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23. Example: Naming Esters
Name the following esters:
Alkyl portion = first name ethyl
Parent carboxylic acid = butanoic acid
Change suffix to reflect ester = Ethyl butanoate
Alkyl portion = first name proply
Parent carboxylic acid = ethanoic acid
Change suffix to reflect ester = Propyl ethanoate
14.2 Esters

24. Naming Esters
Naming esters is much like naming the salts of carboxylic acids:
Alkyl portion = first name ethyl
Parent carboxylic acid = ethanoic acid
Change suffix to reflect ester = Ethyl ethanoate
14.2 Esters

25. Preparing Esters 14.2 Esters 6
Carboxylic acids react with alcohols to produce esters
The reaction is catalyzed by strong mineral acid
Heat is required
A molecule of water is also released as a product: reaction is a dehydration
14.2 Esters
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26. Ester Formation Reaction Example6
14.2 Esters
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27. 14.2 Esters Hydrolysis of Esters 9
The main reaction of esters is hydrolysis, reaction with water
This reaction is also called hydration = cleavage of any bond by the addition of a water molecule
However, the uncatalyzed reaction is slow and requires heat
The reaction can be either acid or base catalyzed
14.2 Esters

28. Acid hydrolysis of Esters
Acid hydrolysis products are:
Acid
Alcohol
14.2 Esters
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29. Base Hydrolysis of Esters10
The base catalyzed hydrolysis of an ester:
Saponification or soap-making
Products are:
Acid salt
Alcohol
Acid can’t exist in basic conditions, so the product is the salt of the carboxylic acid using the cation of the base catalyst
14.2 Esters
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30. Saponification Saponification (soap-making) is:
Base-catalyzed hydrolysis of fats (glycerol triesters)

31. Simplified Action of Soap
The wiggly lines represent the long carbon chains of each soap molecule
Particles of oil and grease are surrounded by soap molecules to form a micelle
14.2 Esters

32. Condensation Polymers
Polyesters are condensation polymers
They are formed by eliminating a small molecule (e.g., H2O) when combining:
Diacid
Diol
Each of the combining molecules has two reactive functional groups, highlighted in red
14.2 Esters

33. Polethylene terphthalate, PETE
1,2-ethanediol
PETE is used in:
Mylar
Plastic bottles
Polyester fabric
Continued condensation
at each end
Repeating unit of the polymer

34. 14.3 Acid Chlorides and Acid Anhydrides11
Acid chlorides are derivatives of carboxylic acids having the general formula:
Are named:
by replacing the –oic acid ending of the IUPAC name with –oyl chloride

35. 14.3 Acid Chlorides and Acid Anhydrides
Acids Chlorides 11
Acid chlorides
Noxious, irritating chemicals requiring great care in handling
Slightly polar, boiling near the corresponding carbonyl’s temperature
React violently with water
Are good acyl group transfer reagents
14.3 Acid Chlorides and Acid Anhydrides

36. 14.3 Acid Chlorides and Acid Anhydrides
Acid anhydrides have the formula:
The molecule is 2 carboxylic acid molecules with a water molecule removed
Anhydride means without water
Symmetrical anhydrides are those with both acyl groups the same
Symmetrical anhydrides are named by replacing the -acid ending of the acid with –anhydride 12
14.3 Acid Chlorides and Acid Anhydrides

37. Formation of Acid Anhydrides
Acid anhydrides are not typically formed in a reaction between the parent carboxylic acids 13
14.3 Acid Chlorides and Acid Anhydrides

38. Acid Chlorides in the Formation of Acid Anhydrides
One reaction used to form acid anhydrides is the combination of a(n):
Acid chloride
Carboxylate anion 13
14.3 Acid Chlorides and Acid Anhydrides

39. Types of Acid Anhydride Reactions With Alcohols
Acid anhydride reacts with alcohol to produce:
Ester
Carboxylic acid
An acyl group transfer reaction
14.3 Acid Chlorides and Acid Anhydrides

40. Acid Anhydride Reaction With Alcohol
14.3 Acid Chlorides and Acid Anhydrides

41. 14.4 Nature’s High Energy Compounds: Phosphoesters and Thioesters
Phosphoric acid reacts with alcohols to produce a phosphate ester or phosphoester
The ester can then react with a second or third acid to give phosphoric acid anhydrides
ADP and ATP of biochemistry fame are important examples of phosphate esters

42. ATP – Adenosine Triphosphate
14.4 Nature’s High Energy Compounds: Phosphoesters and Thioesters
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43. 14.4 Nature’s High Energy Compounds: Phosphoesters and Thioesters
In biochemistry, acetyl coenzyme A (acetyl CoA-SH) reacts with acyl groups to “activate” them for further biological reaction by forming a thioester
14.4 Nature’s High Energy Compounds: Phosphoesters and Thioesters

44. Reaction Schematic

45. Types of Reactions: Summary
1. Carboxylic acids
a. Preparation
b. Dissociation
c. Neutralization
d. Esterification
2. Esters
a. Acid hydrolysis
b. Saponification
3. Acid chloride synthesis
4. Acid anhydride synthesis
5. Phosphoester formation

46. Summary of Reactions Equations