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
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)
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
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!
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
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
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
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
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,
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