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1-1 Chemistry 121, Winter 2012, LA Tech
Introduction to Organic Chemistry and Biochemistry
Instructor Dr. Upali Siriwardane (Ph.D. Ohio State)
E-mail: [email protected]
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(01) Winter 2012
1-2 Chemistry 121, Winter 2012, LA Tech
Chapter 15: Aldehyde and Ketones
Sections
1-3 Chemistry 121, Winter 2012, LA Tech
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
1-4 Chemistry 121, Winter 2012, LA Tech
Carbonyl Group
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1-5 Chemistry 121, Winter 2012, LA Tech
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
Propanone(Acetone)
Ethanal(Acetaldehyde)
Methanal(Formaldehyde)
O O O
CH3 CHHCH CH3 CCH3
1-6 Chemistry 121, Winter 2012, LA Tech
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.
1-7 Chemistry 121, Winter 2012, LA Tech
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
1-8 Chemistry 121, Winter 2012, LA Tech
Nomenclature
CHO HO CHO
Cyclopentane-carbaldehyde
trans -4-Hydroxycyclo-
hexanecarbaldehyde
14
3-Methylbutanal 2-Propenal(Acrolein)
H
O
(2E)-3,7-Dimethyl-2,6-octadienal
(Geranial)
1
2
3
4
5
6
7
8
11
223
3
4H
O
H
O
2-Methyl-cyclohexanone
5-Methyl-3-hexanone
Benzophenone Acetophenone
OO
O O
3
1-9 Chemistry 121, Winter 2012, LA Tech
Nomenclature
HCOOH
O
COOH
O
COOHHO
OHHS
COOH
NH2
-al oxo-
Ketone -one oxo-
Alcohol -ol hydroxy-
Amino -amine amino-
3-Oxopropanoic acid
3-Oxobutanoic acid
4-Hydroxybutanoic acid
3-Aminobutanoic acid
Example of When the FunctionalGroup Has a Lower Priority
Sulfhydryl -thiol mercapto- 2-Mercaptoethanol
Functional Group Suffix Prefix
Carboxyl -oic acid
Aldehyde
1-10 Chemistry 121, Winter 2012, LA Tech
Name the Aldehyde
2,4-dimethylpentanal
1-11 Chemistry 121, Winter 2012, LA Tech
Common Names Aldehydes:
Fomaldehyde: HCHO
Acetaldehyde: CH3CHO
Propionaldehyde: CH3CH2CHO
Butyraldehyde: CH3CH2CH2CHO
Valeraldehyde: CH3CH2CH2CH2CHO
Ketones:
Acetone: CH3COCH3
Methyl ethyl ketone CH3CH2COCH3
Butyl propyl ketone CH3CH2CH2CH2COCH2CH2CH3
1-12 Chemistry 121, Winter 2012, LA Tech
Simplest Aldehyde
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1-13 Chemistry 121, Winter 2012, LA Tech
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:
1-14 Chemistry 121, Winter 2012, LA Tech
Bakelite
1-15 Chemistry 121, Winter 2012, LA Tech
Preapration of Aldehydes:
Partial oxidation of primary alcohols with H2CrO4:
1-16 Chemistry 121, Winter 2012, LA Tech
Preapration of ketones:
Oxidation of secondary alcohols with KMnO4, or
H2CrO4
5
1-17 Chemistry 121, Winter 2012, LA Tech
Oxidation of alcohol
1-18 Chemistry 121, Winter 2012, LA Tech
Oxidation of alcohol
1-19 Chemistry 121, Winter 2012, LA Tech
Physical properties of aldehydes and
ketones.
1-20 Chemistry 121, Winter 2012, LA Tech
Chemical Reactions
Oxidation of aldehyde.
Benedict's Test for aldehydes:
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1-21 Chemistry 121, Winter 2012, LA Tech
Test for Urine Glucose: Benedict’s Test
1-22 Chemistry 121, Winter 2012, LA Tech
Oxidation of aldehyde.
The commercial manufacture of silver
mirrors uses a similar process.
Tollen's Test:
1-23 Chemistry 121, Winter 2012, LA Tech
Reduction of als & ones compounds
to alcohols:
1-24 Chemistry 121, Winter 2012, LA Tech
Addition reactions of als & ones
Hemiacetal or hemiketal formation
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1-25 Chemistry 121, Winter 2012, LA Tech
Hemiacetal form of cyclic sugars
1-26 Chemistry 121, Winter 2012, LA Tech
Formation of Acetals and Ketals.
1-27 Chemistry 121, Winter 2012, LA Tech
Addition of HCN and H2O
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Aldol Condensation
In biological systems this reaction is
catalysed by an enzyme named aldolase.
8
1-29 Chemistry 121, Winter 2012, LA Tech
Keto & Enol tautomers
keto form enol from
1-30 Chemistry 121, Winter 2012, LA Tech
Keto & Enol tautomers in sugars
aldehyde enol ketone
