Download Aldehydes and Ketones

Aldehydes and Ketones
 In an aldehyde, a carbon group and an H atom is
attached to a carbonyl group
O

CH3 - C - H
carbonyl group
carbonyl group always joined to at least
one hydrogen (meaning it is always on
the end!)
Aldehydes and Ketones
 In a ketone, two carbon groups are attached to a
carbonyl group
O
carbonyl group

CH3 - C - CH3
carbon of the carbonyl group is joined to
two other carbons (meaning it is never
on the end)
Naming Aldehydes
 IUPAC Replace the -e in the alkane name with –al
 Common Add aldehyde to the prefixes form (1C),
acet (2C), propion(3), and butry(4C)
O

H-C-H
methanal
O

CH3-C-H
ethanal
O

CH3CH2C-H
propanal
(formaldehyde) (acetaldehyde) (propionaldehyde)
Methanal

common name: formaldehyde
 40%
in water is formalin, a
preservative
Aldehydes as Flavorings
O
O
CH
CH
O
CH=CH CH
HO
OCH3
Benzaldehyde
(almonds)
Vanillin
(vanilla beans)
Cinnamaldehyde
(cinnamon)
Glucose is an aldehyde
O
H
C
H C OH
HO C H
H C OH
H C OH
CH 2OH
glucose
Naming Ketones
 In the IUPAC name, the -e in the alkane name is
replaced with -one
 In the common name, add the word ketone
after naming the alkyl groups attached to the
O
carbonyl group
O

CH3 -C-CH3
O

CH3-C-CH2-CH3
Propanone
2-Butanone
Cyclohexanone
(Dimethyl ketone) (Ethyl methyl ketone)
Propanone
 Common
name: acetone
 nail-polish remover
 miscible with water in all
proportions
Ketones
O O

Butter flavor
CH3-C-C-CH3
O
butanedione

Clove flavor
CH3-C-CH2CH2CH2CH2CH3
2-heptanone
Fructose is a Ketone
CH 2OH
C
HO
O
C H
H
C
OH
H
C
OH
CH 2OH
D-Fructose
Ketones as Hormones
CH2OH
O
CH3
O
OH
CH3
O
Cortisone
Aldehydes and Ketones
 Neither
can form intermolecular
hydrogen bonds, thus a much lower
b.p. than corresponding alcohols
Learning Check
Classify each as an aldehyde (1), ketone (2)
or neither(3).
O

A. CH3CH2CCH3
CH3
O
O

C. CH3-C-CH2CH
CH3
B. CH3-O-CH3
D.
Solution
Classify each as an aldehyde (1), ketone (2)
or neither(3).
O

A. CH3CH2CCH3
CH3
2
O

C. CH3-C-CH2CH 1
CH3
B. CH3-O-CH3 3
D.
O
2
Learning Check
Name the following
O

O
A. CH3CH2CCH3
CH3
O

C. CH3-C-CH2CH
CH3
B.
Solution
O
O

A. CH3CH2CCH3
B.
2-butanone (ethyl methyl ketone)
CH3
O

C. CH3-C-CH2CH
CH3
3,3-dimethylbutanal
cyclohexanone
Learning Check
Draw the structural formulas for each:
A. 3-Methylpentanal
B. 2,3-Dichloropropanal
C. 3-Methyl-2-butanone
Solution
Draw the structural formulas for each:
CH3
O

A. 3-Methylpentanal
B. 2,3-Dichloropropanal
CH3CH2CHCH2CH
Cl O

Cl-CH2CHCH
C. 3-Methyl-2-butanone
O

CH3CHCCH3
CH