This document provides information on the nomenclature, physical properties, synthesis, and characteristic reactions of ketones and aldehydes. It begins with the general structures of ketones and aldehydes and discusses their IUPAC and common nomenclature. It then covers the physical properties and boiling points of ketones and aldehydes compared to other organic compounds. The document concludes with sections on the synthesis of ketones and aldehydes through various reactions like oxidation, hydration, and additions. It also outlines characteristic reactions such as reductions, oxidations, and nucleophilic additions.

1. 1
Ketone Aldehyde
Jully Tan
School of Engineering
EP101 / EG101
Learning Outcome
At the end of this chapter, students are able to:
Provide nomenclature of the ketone and aldehyde
Physical properties of ketone and aldehyde
Synthesis and reaction of ketone and aldehyde

2. 2
The general structure of
the carbonyl group is
C=O
H
R
: :
O
C
The general formula for an aldehyde is
R'
R
And that for a ketone is C=O
: :
C=O
H
H
: :
The R groups can be either alkyl or aryl.
There is also the unique aldehyde, formaldehyde,
in which there are two hydrogen atoms attached to
the carbonyl group.
EP101 / EG101
Nomenclature of Aldehydes
Common names are derived from those of the corresponding carboxylic acids
by dropping the (o)ic acid and adding aldehyde.
H
EXAMPLES: O
EP101 / EG101
OH
O
H
O
Acetic acid Acetaldehyde
O
OH
O
H
Benzoic acid Benzaldehyde
IUPAC (systematic) names are based on the following rules when the
aldehyde function has priority and is named by use of a suffix.
(1) Select the longest continuous chain containing the -CHO and use
as the parent the name of the alkane of that chain length.
(2) Replace e in the alkane name with al.
(3) Number from the end where the carbonyl group is located and
follow all the other rules for locating substituent groups.
H
O
2,2-Dimethylbutanal 4-Phenylpentanal

3. 3
Nomenclature of Ketones
Common names are widely used for many of the simpler ketones.
O=
Acetone, e.g., is the three carbon ketone: CH3CCH3
The common names of other aliphatic ketones are based on the alkyl
group names for R and R' followed by ketone.
EP101 / EG101
O Ethyl methyl ketone
O
Diethyl ketone
Common names of aryl ketones, where a benzene ring (phenyl group)
is attached to the carbonyl, have a phenone ending. The prefix is
derived from the carboxylic acid source of the acyl group.
OH
O
Acetic acid
OH
O
O O
Benzoic acid
Benzophenone
Acetophenone
IUPAC systematic names for ketones are based on
these rules:
(1) The name of the longest alkane chain present that contains the
carbonyl group is used as the parent.
(2) Replace the e in the alkane name with the suffix one and
indicate the carbonyl position by a number. Number from the end
that gives the lower number to the ketone position.
(3) Designate the substituents and their positions in the usual way.
EP101 / EG101
2-Pentanone
2-Methyl-4-phenyl-3-pentanone
O
O
Note use of
alphabetical order.
O
(E)-3-Penten-2-one
Note provision
for C C bond.

4. 4
Physical Properties of Aldehydes and Ketones
Because of the polar carbonyl group (m ~ 2.3-2.8 D), aldehydes and
ketones have higher boiling points than hydrocarbons of comparable size.
However, they have lower boiling points than alcohols of comparable size
because only the latter have intermolecular hydrogen bonds.
O=
O=
CH3CH2CH2CH3 CH3CH2CH CH3CCH3 CH3CH2CH2OH
Butane Propanal Acetone 1-Propanol
MW 58 58 58 60
BP -0.5 oC 49.0 oC 56.1 oC 97.2 oC
Aldehydes and ketones form hydrogen bonds to water molecules and
consequently the lower MW ones are soluble in water up to about C6.
The smallest ones (formaldehyde and acetone) are miscible with water.
EP101 / EG101
O
H
O H
H
O H
Synthesis of Ketones Aldehydes
EP101 / EG101
Oxidation of alcohol
Ozonolysis of alkene
Friedel-crafts acylation
Mercuric catalysed hydration of alkynes
Ketone from nitriles

5. 5
Synthetic Methods for Aldehydes
Because aldehydes are between 1o alcohols and carboxylic acids in the
oxidation-reduction sequence, they can be synthesized by either selective
oxidation of 1o alcohols or by selective reduction of carboxylic acid
derivatives.
[O]
[H]
[O] RCOOH
[H]
O=
RCH2OH RCH
or
RCOX
Reduction of Carboxylic Acids
Aldehydes can be prepared by controlled reduction of carboxylic acids. Acids
can be reduced with lithium aluminum hydride (LAH), a powerful reducing
agent, but the process goes all the way to 1o alcohols.
O=
EP101 / EG101
O=
RCOH
LiAlH4
ether solvent RCH
LiAlH4
facile
RCH2OH
EP101 / EG101
Ozonolysis of alkenes.
C
H
R
C
R'
R''
1)
2)
O3
(CH3)2S
C
H
R
O + O C
R'
R''
Friedel-Crafts acylation
Acid chloride/AlCl3+ benzene ketone
Cyclohexanol Cyclohexanone
Aryl Ketones by Friedel-Crafts Acylation
+
Butanoyl chloride
AlCl3
Phenyl propyl ketone
Cl
O
O

6. 6
Ketones by Hydration of Alkynes
Alkynes, like alkenes, add water in the presence of electrophilic catalysts
such as H+ or Hg2+. Hydration of alkynes is conducted in aqueous
solutions of sulfuric acid with mercuric sulfate as catalyst. It follows
Markovnikov's rule, with the hydrogen attaching to the carbon with the
greater number of hydrogens.
O =
EP101 / EG101
-C C-Alkyne
+ H2O
HgSO4
H2SO4
-C=C-H
OH
Enol
(or vinylic alcohol)
fast -C-C-H
H
The enol rapidly rearranges to the ketone. The enol and ketone
Ketones from Nitriles
Reaction of a nitrile with either a Grignard or organolithium reagent,
followed by hydrolysis, yields a ketone.
N-M
=
O=
EP101 / EG101
d-d+
R-C N:
Nitrile
(R = alkyl or aryl)
+ R'-M ether R-C-R'
Imine salt
R-C-R'
H3O+
H2O
The nitrile is a polar function similar to a carbonyl. The carbanionic
center of an organometallic reagent adds to the electropositive carbon of
the nitrile producing the salt of an imine.
During aqueous workup, the imine is hydrolyzed to a ketone.
:
R-C=N-M
+ H-O-H R-C=N-R'
H
:
Imine
hydrolysis R-C=O:
R'
:
R' d- d+
d- d+

7. 7
(2) H3O+
EP101 / EG101
Examples
Butanenitrile
(1) ether
(2) H3O+
+
O
Butyrophenone
(Phenyl propyl ketone)
MgBr
N
Benzonitrile
N: +
Li
(1) ether
Characteristic Reactions of Aldehydes and Ketones
EP101 / EG101
Reduction reactions
Alcohol formation
Alkane formation
Oxidation reactions
Nucleophilic addition reactions
Grignard additions to form alcohols
Addition of water (hydration) to form gem-diols
Addition of alcohols to form acetals/ketals

8. 8
Reduction Reactions of Aldehydes and Ketones
LiAlH4
ether
H2O
H+
conc. HCl
Zn(Hg)
NH2NH2
OH- / H2O
EP101 / EG101
Alcohol formation
Hydrogenation
Hydride reduction
Alkane formation
Clemmensen reduction
Wolff-Kishner reduction
R C
O
H
H2 / Pt
R CH2OH
R C
O
H R CH2OH
R C
O
H R CH3
R C
O
H R CH3
Oxidation of Aldehydes and Ketones
Conversion of Aldehydes to Carboxylic acids
Oxidation of Aromatic Aldehydes/Ketones to Benzoic acid derivatives
Haloform reaction of methyl carbonyls
EP101 / EG101

9. 9
Aldehyde / Ketone Oxidations
+
Ag(NH3)2
or H (ArCOOH)
RCOOH + HCOOH + HIO
EP101 / EG101
R C
O
H RCOOH
(Tollens reagent)
C
O
H
or
C
O
R
COOH
KMnO4 or K2Cr2O7
²
CH3 C
O
R
X2
OH- / H2O
HCX3 + RCOO -
Ar C
O
Aldehyde / KetoneNucleophilic Addition Reactions
R
R'
gem diol
EP101 / EG101
R C R'
O
RMgX
H +
H 2O
R C
OH
R'
R
R C R'
O
R C R'
O
H + or OH -
H 2O C
OH
OH
dry HCl
R''OH
C
R
R'
OH
OR
C
R
R'
OR
OR
hemiketal ketal
R OH

10. 10
Ketals: Acetals of Ketones
Acetal (ketal) formation with ketones is generally not a favorable process:
C
R'
R
OR''
OR''
+ H2O
H+
EP101 / EG101
C=O
R'
R
+ 2 R''OH
Ketone H+ Ketal
As in the hydration reaction, the equilibrium heavily
favors the ketone.