1. Chapter 13: Aldehydes and Ketones

2. Before you can learn about aldehydes and ketones, you must first know something about the nomenclature of carboxylic acids since many of the names of aldehydes and ketones are derived from the names of the corresponding carboxylic acids.
Carboxylic acids:
R-COOH, R-CO2H,
Common names:
HCO2H formic acid formica ant
CH3CO2H acetic acid acetum vinegar
CH3CH2CO2H propionic acid “first salt”
CH3CH2CH2CO2H butyric acid butyrum butter
CH3CH2CH2CH2CO2H valeric acid valerans

3. ALDEHYDES COMMON NAMES
STEM PLUS ALDEHYDE
HCHO
HCO2H
FORMALDEHYDE
FORMICA - ANTS
FORMIC ACID
CH3CHO
CH3COOH
ACETALDEHYDE
ACETUM - SOUR
ACETIC ACID
CH3CH2CHO
CH3CH2CO2H
PROPIONALDEHYDE
PROTOS PION - FIRST FAT
PROPIONIC ACID
CH3CH2CH2CO2H
CH3CH2CH2CHO
BUTYRALDEHYDE
BUTRYM - BUTTER
BUTYRIC ACID
CH3CH2CH2CH2CH2CHO
CH3CH2CH2CH2CH2CO2H
CAPROALDEHYDE
CAPER - GOAT
CAPROIC ACID

4. Naming Aldehydes IUPAC: Replace -e with -al.
The aldehyde carbon is number 1.
If -CHO is attached to a ring, use the suffix - carbaldehyde.
Chapter 18

5. Common Formaldehyde Acetaldehyde Propionaldehyde Butyraldehyde
IUPAC Methanal Ethanal Propanal Butanal

6. Nomenclature

7. Aromatic aldehydes are usually designated as derivatives of the simplest aromatic aldehyde, Benzaldehyde.
Benzaldehyde p-Nitrobenzaldehyde o-Hydroxybenzaldehyde p-Methoxtbenzaldehyde

8. Ketones: Structure and Nomenclature
General formula: RCOR’ (R and R’=alkyl or aryl)
Common name: listing the alkyl substitutents attached to the carbonyl group, followed by the word ketone.
IUPAC system: relpace the ending –e by the suffix –one. The chain is numbred in such a way as give the lowest number to the C=O group.
Common Dimethyl ketone Methyl phenyl ketone Methyl vinyl ketone Diphenyl ketone
Acetone Acetophenone Benzophenone
IUPAC Propanone Phenyl ethanone Buten-2-one Diphenylmethanone

10. (o)phenones:
Derived from common name of carboxylic acid, drop –ic acid, add –(o)phenone.

12. Cyclopentylpropanone 3-Ethyl-2-hydroxycyclohexanone 5-Oxohexanal

13. Boiling Points
More polar, so higher boiling point than comparable alkane or ether.
Cannot H-bond to each other, so lower boiling point than comparable alcohol.
=>
Chapter 18

14. Solubility Good solvent for alcohols.
Lone pair of electrons on oxygen of carbonyl can accept a hydrogen bond from O-H or N-H.
Acetone and acetaldehyde are miscible in water =>
Chapter 18

15. Aldehydes synthesis 1) oxidation of primary alcohols:
RCH2-OH K2Cr2O7 (potassium dichromate)  RCH=O+ H2
RCH2-OH C5H5NHCrO3Cl  RCH=O+ H2
(pyridinium chlorochromate, or PCC)
[With other oxidizing agents, primary alcohols  RCOOH]

16. Aldehyde synthesis: Primary alcohols

17. Aldehyde synthesis: 2) reduction of acid chloride

19. Ketone synthesis: 1) oxidation of secondary alcohols

20. Ketone synthesis: 2) Friedel-Crafts acylation
Aromatic ketones (phenones) only!

21. Friedel Crafts acylation does not work on deactivated rings.

22. Acetals andHemicetals
Acetal: two –OR groups bonded to the same carbon
Hemiacetal: one –OR group and one –OH group bonded to the same carbon

23. Enolization Keto-Enol Tautomerism
Tautomerism: interconversion between two structures that differ by the placement of an atom or group
Slow in neutral conditions, sped up in acid or base catalyzed systems
Enol content is very small, <<<1% for most aldehydes and ketones