Carboxylic Acids: Properties and Synthesis

1
Carboxylic AcidsProperties and Synthesis

• Chapter 18

2
Assignments

• In-text problems
• 18-1 and 18-2
• 18-4 (IUPAC only!!)
• 18-6 to 18-10 18-14 to 18-20
• End-of-chapter problems
• 1
• 3 to 9
• 11 to 16

3
Sect. 18.1 IUPAC Nomenclature

• -oic acid IUPAC ending
• -carboxylic acid IUPAC ending for ring compounds

4

• 3-Methylbutanoic acid

5

• 2-Chloropentanoic acid

6
4-methoxy-3,5-hexadienoic acid
7

• Cyclohexanecarboxylic acid

8
3-methylcyclohexanecarboxylic acid
9

• Benzoic acid
• or Benzenecarboxylic acid

10
Numbering system
11
2-chlorobenzoic acid or 2-chlorobenzenecarboxylic
acid
12
Common names for benzoic acids
13
Common names!
ortho-chlorobenzoic acid
o-chlorobenzoic acid
14
IUPAC only
3-chloro-2-nitrobenzoic acid or
3-chloro-2-nitrobenzenecarboxylic acid
15
IUPAC only
3-(3-nitrophenyl)propanoic acid
16
Common Names
17
Some more common names

• butyric acid and isobutyric acid
• valeric acid and isovaleric acid
• Fatty acids myristic, palmitic and stearic acids

18

• 2-Methylpropanoic acid
• Isobutyric acid

19
Fatty acids
20
Sect. 18.2 carboxylate salts

• endings oate
• combine with sodium, potassium etc.
• Example sodium butanoate (IUPAC) or sodium
  butyrate (common)

21
Carboxylate Ion Formation
22
Sect. 18.3 hydrogen bonding
Carboxylic acids are very high boiling! Low MW
acids are water soluble and High MW acids are
water insoluble!
23
Sections 18.4, 18.5, 18.6

• Much of this material is review!
• Key table Table 18-18 on page 62!!
• Skip Section 18.7.

24
Resonance Effects
Effect Acid Base Examples
Electron withdrawing by resonance (-R)
weaken
strengthen
releasing by Resonance (R)
Electron
weaken
strengthen
25
Electron-withdrawing effects involving resonance
(-R) These substituents strengthen acids and
weaken bases on the benzene ring
26
Substituents with Electron-Withdrawing Resonance
Effects
27

• Electron-withdrawing Effects
• strengthen acids
• weaken bases

28
A substituted benzoic acid
29
Electron releasing effect by resonance (R)
These substituents weaken acids and strengthen
bases on the benzene ring
30
Substituents with Electron-Releasing Resonance
Effects
31
Electron-releasing Effects - weaken acids -
strengthen bases
32
Substituted benzoic acid
33
Benzoic Acid pKa 4.19
34
Inductive Effect
Effect Acid Base Examples
weaken
strengthen
Electron withdrawing by inductive effect (-I)
electron
releasing by inductive effect (I)
weaken
strengthen
35
Electron withdrawing by inductive effects (-I)
These substituents strengthen acids and weaken
bases
36
Substituents with Electron-Withdrawing Inductive
Effects on substituted acetic acids
37
(No Transcript)
38
Inductive and resonance
Inductive, only
Resonance and weak inductive
Benzoic Acid pKa 4.19
39
Another substituted benzoic acid

• 4-chlorobenzoic acid is weird!! Resonance effect
  will decrease acidity, but inductive effect wins
  out.

40
Electron releasing effect by inductive effect
(I) These substituents weaken acids and
strengthen bases
41
Substituents with Electron-Releasing Inductive
Effects
42
(No Transcript)
43
Benzoic Acid pKa 4.19
44
Sect. 18.8 Carbonation of Grignard Reagents
45
Sect. 18.9 Formation of Nitriles
46
Hydrolysis of Nitriles
47
Sect. 18.10 Oxidation of Primary Alcohols
48
Oxidation of Side Chains
49
(No Transcript)