1. Three methods are outlined for synthesizing benzaldehyde: oxidation of benzyl alcohol with K2Cr2O7 under special conditions, oxidation of toluene with CrO3 and diacetate, and reduction of benzoyl chloride with LiAlH(O-t-Bu)3. 2. Three methods are outlined for synthesizing benzophenone: oxidation of benzhydrol with NaOCl, Friedel-Crafts acylation of benzene with benzoyl chloride using AlCl3, and coupling benzoyl chloride with lithium diethylcuprate. 3. A different synthesis method is outlined for each of cyclohexanone, 4-brom

1. KOHINOOR COLLEGE KHULTABAD
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Power point presentation on
ALDEHYDES AND KETONES

2. Carboxylic acids:
R-COOH, R-CO2H,
Common names:
HCO2H formic acid L. formica ant
CH3CO2H acetic acid L. acetum vinegar
CH3CH2CO2H propionic acid G. “first salt”
CH3CH2CH2CO2H butyric acid L. butyrum butter
CH3CH2CH2CH2CO2H valeric acid L. valerans
R C
OH
O
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.

3. Carboxylic acids, common names:
…
CH3(CH2)4CO2H caproic acid L. caper goat
CH3(CH2)5CO2H ---
CH3(CH2)6CO2H caprylic acid
CH3(CH2)7CO2H ---
CH3(CH2)8CO2H capric acid
CH3(CH2)9CO2H ---
CH3(CH2)10CO2H lauric acid oil of lauryl

4. 5 4 3 2 1
C—C—C—C—C=O
δ γ β α used in common names
CH3CH2CH2CHCOOH
Br
CH3CHCH2COOH
CH3
 bromovaleric acid -methylbutyric acid
isovaleric acid

5. COOH
COOH COOH COOH
CH3
CH3
CH3
benzoic acid
o-toluic acid m-toluic acid p-toluic acid
Special names!

6. ALDEHYDES AND KETONES
“carbonyl” functional group:
Ketones
H
C
H
O
R
C
H
O
R
C
R'
O
R can be Ar
C
O
Aldehydes ;

7. Nomenclature:
Aldehydes, common names:
Derived from the common names of carboxylic acids;
drop –ic acid suffix and add –aldehyde.
CH3
CH3CH2CH2CH=O CH3CHCH=O
butyraldehyde isobutyraldehyde
(α-methylpropionaldehyde)

8. CHO
benzaldehyde
CHO
CH3
o-tolualdehyde
H
C
H
O
formaldehyde
CH2CH=O
phenylacetaldehyde

9. Aldehydes, IUPAC nomenclature:
Parent chain = longest continuous carbon chain containing
the carbonyl group; alkane, drop –e, add –al. (note: no
locant, -CH=O is carbon #1.)
CH3
CH3CH2CH2CH=O CH3CHCH=O
butanal 2-methylpropanal
H2C=O CH3CH=O
methanal ethanal

10. Ketones, common names:
Special name: acetone
“alkyl alkyl ketone” or “dialkyl ketone”
H3C
C
CH3
O
CH3CH2CCH3
O
CH3CH2CCH2CH3
O
ethyl methyl ketone diethyl ketone
CH3CCH2CH2CH3
O
methyl n-propyl ketone

11. (o)phenones:
Derived from common name of carboxylic acid, drop –
ic acid, add –(o)phenone.
C
R
O
C
O
H3C
C
O
benzophenone acetophenone

12. Ketones: IUPAC nomenclature:
Parent = longest continuous carbon chain containing the
carbonyl group. Alkane, drop –e, add –one. Prefix a
locant for the position of the carbonyl using the principle
of lower number.
CH3CH2CCH3
O
CH3CH2CCH2CH3
O
2-butanone 3-pentanone
CH3CCH2CH2CH3
O
2-pentanone

13. Physical properties:
polar, no hydrogen bonding
mp/bp are relatively moderate for covalent substances
water insoluble
(except: four-carbons or less)
C O sp2 120o
C O C O


14. Spectroscopy:
IR: C=O stretch, strong ~1700 cm-1
RCHO 1725 ArCHO 1700
R2CO 1710 ArCOR 1690
C—H stretch for aldehydes 2720
nmr: -CHO 9-10 ppm

15. C=O
stretch
acetophenone

16. valeraldehyde
CHO
C—H
stretch
2720 cm-1
C=O stretch

17. valeraldehyde
CH3CH2CH2CH2CH=O
a b c d e
-CHO

18. Oxidation/Reduction:
oxidation numbers:
oxidation
-4 -2 0 +2 +4
CH4 CH3OH H2C=O HCO2H CO2
alkane alcohol aldehyde carboxylic acid
reduction

19. Aldehydes, syntheses:
1. Oxidation of 1o alcohols
2. Oxidation of methylaromatics
3. Reduction of acid chlorides
Ketones, syntheses:
1. Oxidation of 2o alcohols
2. Friedel-Crafts acylation
3. Coupling of R2CuLi with acid chloride

20. Aldehydes synthesis 1) oxidation of primary alcohols:
RCH2-OH + K2Cr2O7, special conditions  RCH=O
RCH2-OH + C5H5NHCrO3Cl  RCH=O
(pyridinium chlorochromate)
[With other oxidizing agents, primary alcohols 
RCOOH]

21. CH3CH2CH2CH2CH2OH
+ K2Cr2O7 CH3CH2CH2CH2CO2H
1-pentanol
pentanoic acid
K2Cr2O7, special conditions!
CH3CH2CH2CH2CH=O
pentanal
valeraldehyde
CH2OH
C5H5NHCrO3Cl
pyridinium chlorochromate
CH=O
benzaldehyde
benzyl alcohol
CH3CH2CH2CH2CH2OH
1-pentanol

22. Aldehyde synthesis: 2) oxidation of methylaromatics:
+ CrO3, (CH3CO)2O
geminal diacetate
H2O, H+
CH3
Br
Br
CH O
O
C C
H3C
O
O
H3C
Br
CHO
p-bromobenzaldehyde
Aromatic aldehydes only!

23. CH3
CH3O CH3
CrO3
(CH3CO)2O
CrO3
(CH3CO)2O
H2O
H2O
CHO
CH3O CH=O
2-methylnaphthalene 2-naphthaldehyde
p-methylanisole p-anisaldehyde

24. Aldehyde synthesis: 3) reduction of acid chloride
LiAlH(O-t-Bu)3
lithium aluminum hydride tri-tert-butoxide
O
Cl
isovaleryl chloride
O
H
isovaleraldehyde
R
C
O
Cl
LiAlH(O-t-Bu)3
R
C
O
H

25. C
O
Cl
LiAlH(O-t-Bu)3
C
O
H
LiAlH(O-t-Bu)3
benzoyl chloride benzaldehyde
CH3CHCH2C
O
Cl
CH3
CH3CHCH2C
O
H
CH3
isovaleryl chloride isovaleraldehyde

26. Ketone synthesis: 1) oxidation of secondary alcohols
NaOCl
cyclohexanol cyclohexanone
isopropyl alcohol acetone
K2Cr2O7
H OH O
H3C
C
CH3
O
CH3CHCH3
OH

27. Ketone synthesis: 2) Friedel-Crafts acylation
RCOCl, AlCl3 + ArH + HCl
AlCl3
Ar
C
R
O
Aromatic ketones (phenones) only!
CH3CH2CH2C
O
Cl
+
AlCl3
CH3CH2CH2C
O
butyrophenone

28. +
AlCl3
m-nitrobenzophenone
O2N
C Cl
O
C
O
O2N
+
AlCl3
C Cl
O
NO2
NR
Friedel Crafts acylation does not work on deactivated rings.

29. Mechanism for Friedel-Crafts acylation EAS
R
C
Cl
O
+ AlCl3 RC=O + AlCl4
+ RC=O
RDS
H
CR
O
H
CR
O
+ AlCl4
C R
O
+ HCl + AlCl3

30. Ketone synthesis: 3) coupling of RCOCl and R2CuLi
RCOCl + R'2CuLi
R
C
O
R'
Cl
O
+ (CH3CH2)2CuLi
O
Isobutyryl chloride 2-Methyl-3-pentanone
lithium diethylcuprate

31. CuLi
2
+ CHCH2CH2CH3
O
Cl
CCH2CH2CH3
O
butyrophenone
CH3CH2CH2C
O
Cl
+ CH3CH
CH3
2
CuLi CH3CH2CH2CCHCH3
O
CH3
2-methyl-3-hexanone

32. Aldehydes, syntheses:
1. Oxidation of 1o alcohols
2. Oxidation of methylaromatics aromatic only
3. Reduction of acid chlorides
Ketones, syntheses:
1. Oxidation of 2o alcohols
2. Friedel-Crafts acylation aromatic only
3. Coupling of R2CuLi with acid chloride

33. aldehyde
1o alcohol
Ar-CH3
acid chloride
CrO3 H2O
(AcO)2O
LiAlH(O-t-Bu)3
K2Cr2O7, special cond.
or C5H5NHCrO3Cl

34. ketone
2o alcohol
acid chloride + ArH
acid chloride + R2CuLi
NaOCl, etc.
AlCl3

35. 1. outline three different syntheses for benzaldehyde
2. outline three different syntheses for benzophenone
3. outline a different synthesis for each of the
following compounds:
cyclohexanone, 4-bromobenzaldehyde, 2-pentanone,
valeraldehyde, acetophenone, isobutyraldehyde,

36. CH2OH
K2Cr2O7
special conditions
CH3
CrO3
(CH3CO)2O
CH(OOCCH3)2
H2O
C
O
Cl
LiAlH(O-t-Bu)3
CH=O
benzaldehyde
Synthesize benzaldehyde three different ways.

37. CH
OH NaOCl
C
O
Cl
+
AlCl3
C
O
Cl
+ CuLi
2
C
O
Synthesize benzophenone three different ways.

38. cyclohexanone, 4-bromobenzaldehyde, 2-pentanone,
valeraldehyde, acetophenone, isobutyraldehyde, using a
different method for each one.
O
Br CHO
CH3CH2CH2CCH3
O
CH3CH2CH2CH2CHO
CH3C
O
CH3CHCHO
CH3
oxidation of 2o
alcohol oxidation of Ar-CH3
R2CuLi + R'COCl
Friedel-Crafts acylation
oxidation of 1o alcohol
reduction of acid chloride

39. O
CH3CH2CH2CCH3
O
CH3C
O
OH
H
K2Cr2O7
CH3 C
Cl
O
+
AlCl3
(CH3CH2CH2)CuLi + CH3 C
Cl
O

40. Br CHO
CH3CH2CH2CH2CHO
CH3CHCHO
CH3
Br CH3
CH3CH2CH2CH2CH2-OH
K2Cr2O7
special conditions
CrO3
(CH3CO)2O
H2O
CH3CHC
CH3 O
Cl
LiAlH(O-t-bu)3
The methods could be reversed for the last two syntheses.