Chemistry 121(01) Winter 2012
Introduction to Organic Chemistry and Biochemistry
Instructor Dr. Upali Siriwardane (Ph.D. Ohio State)
E-mail: upali@chem.latech.edu
Office: 311 Carson Taylor Hall ; Phone: 318-257-4941;
Office Hours: MTW 9:00 am - 11:00 am;
TR 9:00 - 10:00 am & 1:00-2:00 pm.
December 16, Test 1 (Chapters 12-13)
January 20 Test 2 (Chapters 14-16)
February 6 (Chapters 17-19)
February 27, (Chapters 20-22)
February 28, 2012, Make Up Exam:
Bring Scantron Sheet 882-E
Chemistry 121, Winter 2012, LA Tech
1-1
Chapter 15: Aldehyde and Ketones
Sections
Chemistry 121, Winter 2012, LA Tech
1-2
Chapter 15: Aldehyde and Ketones
15.1 The Carbonyl Group
15.2 Structure of Aldehydes and Ketones
15.3 Nomenclature for Aldehydes
15.4 Nomenclature for Ketones
15.5 Isomerism for Aldehydes and Ketones
15.6 Selected Common Aldehydes and Ketones
15.7 Physical Properties of Aldehydes and Ketones
15.8 Preparation of Aldehydes and Ketones
15.9 Oxidation and Reduction of Aldehydes and Ketones
15.10 Reaction of Aldehydes and Ketones with Alcohols
Chemistry 121, Winter 2012, LA Tech
1-3
Carbonyl Group
Chemistry 121, Winter 2012, LA Tech
1-4
Structure
• the functional group of an aldehyde is a carbonyl group
bonded to a H atom
• the functional group of a ketone is a carbonyl group
bonded to two carbon atoms
O
HCH
Methanal
(Formaldehyde)
Chemistry 121, Winter 2012, LA Tech
O
CH3 CH
Ethanal
(Acetaldehyde)
O
CH3 CCH3
Propanone
(Acetone)
1-5
IUPAC Nomenclature of Aldehyde and
Ketones
The IUPAC system deals with functional
groups two different ways.
Modification of the hydrocarbon name to
indicate the presence of a functional group.
aldehyde, -CHO
use -al ending.
Ketones -RCOR’
use -one ending.
Chemistry 121, Winter 2012, LA Tech
1-6
Example
C - C - C - C - CHO
Base contains 5 carbon
- aldehyde name is pentane
- remove -e and add -al
C - C - C - C - CO-C-C
Base contains 7 carbon
- aldehyde name is heptane
- remove -e and add -one
3-heptanone
Chemistry 121, Winter 2012, LA Tech
1-7
Nomenclature
O
O
3
4
2
3
H
3-Methylbutan al
CHO
2-Methylcycloh exanone
Chemistry 121, Winter 2012, LA Tech
6
3
4
1
2
H
(2E)-3,7-D imeth yl-2,6-octad ienal
(Geran ial)
1
CHO
trans -4-Hyd roxycyclohexan ecarbald ehyde
O
O
8
2-Propen al
(A crolein )
4
5
7
H
2
HO
Cyclopen tanecarb aldehyde
5-Methyl-3h exanone
O
1
1
O
Acetop hen on e
O
Benzoph enone
1-8
Nomenclature
Functional
Grou p
Su ffix
Carb oxyl
-oic acid
Ald ehyde
-al
Prefix
Example of When the Fun ction al
Grou p Has a Low er Priority
O
oxo-
3-Oxopropan oic acid
COOH
H
O
COOH
Ketone
-one
oxo-
3-Oxobutanoic acid
Alcoh ol
-ol
hydroxy-
4-Hydroxybutan oic acid HO
COOH
NH2
Amino
-amine
Su lfh ydryl -thiol
Chemistry 121, Winter 2012, LA Tech
amino-
COOH
3-Aminobutan oic acid
mercapto- 2-Mercaptoethanol
HS
OH
1-9
Name the Aldehyde
2,4-dimethylpentanal
Chemistry 121, Winter 2012, LA Tech
1-10
Common Names
Aldehydes:
Fomaldehyde:
HCHO
Acetaldehyde:
CH3CHO
Propionaldehyde:
CH3CH2CHO
Butyraldehyde:
CH3CH2CH2CHO
Valeraldehyde:
CH3CH2CH2CH2CHO
Ketones:
Acetone:
CH3COCH3
Methyl ethyl ketone
CH3CH2COCH3
Butyl propyl ketone
CH3CH2CH2CH2COCH2CH2CH3
Chemistry 121, Winter 2012, LA Tech
1-11
Simplest Aldehyde
Chemistry 121, Winter 2012, LA Tech
1-12
Important Aldehydes
Methanal or formaldehyde
Ethanal or acetaldehyde
2-Propanone or acetone
2-Butanone or methyl ethyl ketone
Oil of almonds or benzaldehyde
Oil of Cinnamon or cinnamaldehyde
Oil of vanilla beans or vanillin
Mushroom flavoring or 2-octanone
Oil of lemongrass or citral:
Chemistry 121, Winter 2012, LA Tech
1-13
Bakelite
Chemistry 121, Winter 2012, LA Tech
1-14
Preapration of Aldehydes:
Partial oxidation of primary alcohols with H2CrO4:
Chemistry 121, Winter 2012, LA Tech
1-15
Preapration of ketones:
Oxidation of secondary alcohols with KMnO4, or
H2CrO4
Chemistry 121, Winter 2012, LA Tech
1-16
Oxidation of alcohol
Chemistry 121, Winter 2012, LA Tech
1-17
Oxidation of alcohol
Chemistry 121, Winter 2012, LA Tech
1-18
Physical properties of aldehydes and
ketones.
Chemistry 121, Winter 2012, LA Tech
1-19
Chemical Reactions
Oxidation of aldehyde.
Benedict's Test for aldehydes:
Chemistry 121, Winter 2012, LA Tech
1-20
Test for Urine Glucose: Benedict’s Test
Chemistry 121, Winter 2012, LA Tech
1-21
Tollen's Test:
Oxidation of aldehyde.
The commercial manufacture of silver
mirrors uses a similar process.
Chemistry 121, Winter 2012, LA Tech
1-22
Reduction of als & ones compounds
to alcohols:
Chemistry 121, Winter 2012, LA Tech
1-23
Addition reactions of als & ones
Hemiacetal or hemiketal formation
Chemistry 121, Winter 2012, LA Tech
1-24
Hemiacetal form of cyclic sugars
Chemistry 121, Winter 2012, LA Tech
1-25
Formation of Acetals and Ketals.
Chemistry 121, Winter 2012, LA Tech
1-26
Addition of HCN and H2O
Chemistry 121, Winter 2012, LA Tech
1-27
Aldol Condensation
In biological systems this reaction is
catalysed by an enzyme named aldolase.
Chemistry 121, Winter 2012, LA Tech
1-28
Keto & Enol tautomers
keto form
Chemistry 121, Winter 2012, LA Tech
enol from
1-29
Keto & Enol tautomers in sugars
aldehyde
Chemistry 121, Winter 2012, LA Tech
enol
ketone
1-30