Carbonyl Compounds II:
Chapter 12
Chapter 12
1
Contents of Chapter 12






Structure of Aldehydes and Ketones
Naming Adehydes and Ketones
Reactivity with Nucleophiles
Hydration of Aldehydes and Ketones
Acetals and Ketals
Skip Grignard Reagents, Hydride
Reductions, Reactions With Amines,
Conjugate Additions, and Biological
Reactions
Chapter 12
2
Structure of Aldehydes and
Ketones
or
An aldehyde
A ketone
Chapter 12
3
Nomenclature of
Aldehydes and Ketones

IUPAC Nomenclature of Aldehydes
•
•
•
Select as the parent compound the longest
chain of carbon atoms that contains the
functional group.
For aldehydes, change the suffix –e of the
parent name to –al.
Aldehyde carbon is carbon 1.
Chapter 12
4
Nomenclature of Aldehydes
CH3
CH3
O
CH
C
3
CH2
H
1
2
4
3-Methylbutanal
CH3
CH3
8
C
7
CH
6
CH2
5
CH2
CH3
O
C
C
3
4
CH
1
2
H
trans-3,7-dimethyl-2,6-octadienal
Chapter 12
5
Nomenclature of
Aldehydes and Ketones

IUPAC Nomenclature of Ketones
•
•
•
Select as the parent compound the longest
chain of carbon atoms that contains the
functional group.
For ketones, change the suffix –e of the
parent name to –one.
Number the chain so that the ketone group
gets the lowest number.
Chapter 12
6
Nomenclature of Ketones
O
CH3
C
O
CH3
propanone
(acetone)
CH3
CH2
C
CH
CH2
CH3
CH3
4-methyl-3-hexanone
Chapter 12
7
Nomenclature of Ketones
O
O
C
CH3
CH3
acetophenone
2-methylcyclohexanone
Note: The IUPAC system retains some common names
such as acetone and acetophenone.
Chapter 12
8
Common Names
The common name for an aldehyde is
derived from the common name of the
corresponding carboxylic acid by
changing the suffix –ic to –aldehyde.
O
O
O
O
C
C
C
C
H
OH
H
H
formic acid formaldehyde
CH3
OH
acetic acid
Chapter 12
CH3
H
acetaldehyde
9
Common Names
Common names for ketones are derived by
naming the two alkyl or aryl groups attached to
the carbonyl group, followed by the word
ketone.
O
CH3
CH
C
CH2
CH3
CH3
ethyl isopropyl ketone
Chapter 12
10
Reactions of
Aldehydes and Ketones
Nucleophilic Addition

O
R
C
O
+
H Nu
H
C R
R
Nu
R
The more sterically-hindered the area around
the carbonyl carbon is the less reactive the
aldehyde or ketone is with nucleophiles
Chapter 12
11
Reactions of
Aldehydes and Ketones

Addition of Water
• Aldehydes
O
+ H2O
C
H
H
OH
H C H
OH
• Ketones
OH
O
CH3
C
+ H2O
CH3 C CH3
CH3
OH
Chapter 12
12
Formation of Acetals and
Ketals

Addition of one molecule of alcohol to
an aldehyde forms a hemiacetal:
OH
O
CH3
C
H
H
+
O CH3
CH3 C OCH3
H
a hemiacetal
Chapter 12
13
Formation of Acetals and
Ketals


Hemiacetals and hemiketals react further with
alcohols to form acetals and ketals.
These reactions are acid catalyzed.
OH
H
CH3 C OCH3 + CH3OH
H
a hemiacetal
OCH3
CH3 C OCH3 + H2O
H
1,1-dimethoxyethane
(a dimethyl acetal)
Chapter 12
14
Formation of Acetals and
Ketals
OH
CH3 C OCH2CH3 + CH3CH2OH
CH3
a hemiketal
H
OCH2CH3
CH3 C OCH2CH3 + H2O
CH3
2,2-diethoxypropane
(a diethyl ketal)
Chapter 12
15
Oxidation of
Aldehydes and Ketones
Oxidizing agents commonly used to
oxidize aldehydes to carboxylic
acids are potassium
permanganate and chromic acid
O
R
C
H
KMnO4
or H2CrO4
Chapter 12
O
R
C
OH
16