ALDEHYDES AND KETONES
IN WEEK 1, A STUDENT SHOULD BE ABLE TO:
1.
Give the IUPAC name given the structure, and draw the structure given the name, of
aldehydes and ketones. Also, draw the structure given any of the following common
names: formaldehyde, acetaldehyde, benzaldehyde, acetone, acetophenone, and
benzophenone.
2.
Given the starting material and reaction conditions, predict the products of reactions
giving rise to aldehydes and ketones. Important reactions include:
Oxidation of 1° and 2° alcohols
Ozonolysis of alkenes
Hydroboration of alkynes
Acid-catalyzed hydration of alkynes
3.
Predict the products of the reactions of aldehydes and ketones. Important reactions
include:
Reactions with hydrides (reducing agents such as LiAlH4 and NaBH4)
Reactions with water and alcohols (to form hemiacetals, acetals)
Reactions with derivatives of ammonia (to form oximes, semicarbazides, hydrazones,
imines, and enamines)
Reactions with thiols
Oxidation
Wolff-Kishner reduction of ketones to alkanes, and Clemmensen reduction of
benzylic ketones
4.
Propose syntheses using the reactions of Objectives #2 and #3.
5.
Propose mechanisms of reactions involving nucleophilic attack on the carbonyl carbon.
6.
Predict and interpret spectra.
IN WEEK 2, A STUDENT SHOULD ALSO BE ABLE TO:
7.
Perform the objectives detailed above for these additional reactions with an emphasis on
C-C bond forming reactions in synthesis:
Friedel-Crafts acylation
Reactions with Grignard and organolithium reagents
Reactions with ylides, plus other reactions in the Wittig reaction sequence
To best prepare for this module, please work Chapter 20 Skill Builder problems in the textbook.
A STUDENT WHO HAS MASTERED THE OBJECTIVES FOR THIS UNIT SHOULD BE
ABLE TO SOLVE THE FOLLOWING PROBLEMS AND RELATED ONES:
Problems 1-6 should be mastered for the first week of drill:
1.1
Draw each of the following compounds.
a) acetaldehyde
b) acetophenone
c) 2-methylcyclopentanone
1.2
Name each of the compounds shown.
2.
Predict the product(s) of each of the following reactions.
2.
3.
Predict the product(s) of each of the following reactions:
4.
Propose syntheses of each of the compounds indicated, from the given starting material
and any other needed reagents.
a) 3-methyl-1-butanol from trans-5-methyl-2-hexene
5.
Propose a mechanism for each of the following reactions.
b)
O
+
H2O
H3O+
OH
OH
6.1
Propose structures for each of the following compounds:
a)
C9H10O2
IR:
1695 cm-1
1
H NMR:
triplet, 1.3 (3H)
quartet, 4.1 (2H)
doublet, 6.9 (2H)
doublet, 7.8 (2H)
singlet, 9.9 (1H)
6.1 continued
b)
C10H12O
IR:
1710 cm-1
1
H NMR:
triplet, 1.0 (3H)
quartet, 2.2 (2H)
singlet, 3.8 (2H)
singlet, 7.2 (5H)
7.1
Predict the product(s) of each of these reactions.
7.2
Complete these reactions.
7.2
Li
1.
OH
c)
2. H3O+
PCC
NH2OH, H3O+
7.3
Propose syntheses of each of the compounds indicated.
a) benzaldehyde from benzene
b)
CH2CH=CH2 from
CH2CH=O and
(C6H5)3P
7.3 continued
7.4
Propose a mechanism for this reaction:
SOLUTIONS TO SAMPLE PROBLEMS:
1.1
a) acetaldehyde
b) acetophenone
1.2
a) 4-methyl-2-pentanone or 4-methylpentan-2-one
b) 2-hydroxy-3,3-dimethylcycloheptanone
c) 3-chloropropanal
c) 2-methylcyclopentanone
2.
3.
The reactions give these products:
3.
O
g)
+ NH2NH2
H+
O
h)
4.
KOH/H2O
heat
N
(CH3CH2)2NH
dil. H+
N
+
major
minor
4.
5.
Mechanisms:
-
OCH3
a)
O
+
CH3O
HOCH3
CH3O-
+
HO
basic solution: neutrals and
anions, not cations
OCH3
H
O-
CH3
O
H
H
O
b)
+
H2O
O
OH
H
acidic solution: neutrals
and cations, not anions
OH
OH
OH
OH2
O
H
6.1
H
OH2
Unknowns:
a) CH3CH2O
CH=O
b)
CH2COCH2CH3
7.1
7.2
7.2
7.3
a)
CH3Cl
AlCl3
1. Br2, heat
2. NaOH
OH
PCC
Br2,
FeBr3
Br
MgBr
1. H2C=O
2. H3O+
O
Mg, ether
Also: oxidize toluene to benzoic acid; reduce with LAH to benzyl alcohol; then PCC.
**This cannot be done in one step via Friedel Craf ts acylation; ClCH=O is not stable.**
d)
(C6H5)3P + CH3CH2Br
(C6H5)3P+CH2CH3 Br-
(C6H5)3P+CH2CH3 Br- + NaNH2
(C6H5)3P=CHCH3 + C6H5CH2CH=O
(C6H5)3P=CHCH3
C6H5CH2CH=CHCH3 + O=PPh3
7.3
7.4
OMgBr
O
+ 2 CH3MgBr
+ CH3CH2OMgBr
C
OCH2CH3
OMgBr
O
+ CH3MgBr
OCH2CH3
OCH2CH3
OMgBr
OCH2CH3
O
+ CH3CH2OMgBr
OMgBr
O
+ CH3MgBr
C
Name ________________________________________________ Drill Test 6.1 (Sample A)
Organic Chemistry 2220D
Answer All Questions
1.
Draw the structure of: p-nitroacetophenone
2.
Give the IUPAC name of:
3.
a)
Predict the products of these reactions:
b)
c)
d)
e)
4.
Propose complete mechanisms for these reactions. Include all intermediates and arrows.
5.
Propose syntheses for these compounds:
a) 2-butanol from 3-methyl-3-heptene
b)
6. Draw the structure for a compound that is consistent with these data:
IR: 2950 cm-1; 1750 cm-1
13
C NMR: 212, 42, 27, 18 ppm
1
H NMR: 2.6 ppm, septet, 1H; 2.1 ppm, singlet, 3H; 1.1 ppm, doublet, 6H
m/z of molecular ion: 86
Name ______________________________________________
Organic Chemistry 2220D
1.
What is the IUPAC name of:
3.
Predict the products of these reactions:
2.
Drill Test 6.1 (Sample B)
Answer All Questions
Draw the structure of:
2,2,2-trichloroacetaldehyde
3.
4.
Propose syntheses for:
a) benzaldehyde from benzyl chloride
c) CH3CH2CH2CH=NH
from
CH3CH2C≡CH
5. Draw a mechanism for each of these reactions:
6. Predict the IR and 1H NMR spectra of 3-pentanone.
Name ________________________________________________ Drill Test 6.2 (Sample A)
Organic Chemistry 2220D
Answer All Questions
1.
Name:
O
Cl
Cl
2.
3.
Draw the structure of:
a) 1,1-diiodo-3-pentanone
b) 2-hydroxypropanal
Predict the product or products (if any) of each of the following reactions.
a)
+
OH
CrO3
H2SO4
d) CH3CH2C≡CH + HgSO4, H2SO4, H2O
4.
Propose a synthesis of each of the compounds shown, from the given starting material
and any other needed reagents.
S
S
a)
b)
from
f rom
c)
(C6H5)3P and CH3Cl
f rom
O
Br
Name ______________________________________________
Organic Chemistry 2220D
Drill Test 6.2 (Sample B)
Answer All Questions
1.
Which of the following compounds gives a new product on reaction with H2CrO4, and
decolorizes Br2 in CCl4?
2.
Give the IUPAC name for the
following compound.
4.
Predict the product of each of the following reactions.
5.
Propose a synthesis of each of the compounds indicated from the given starting materials
and any other needed reagents.
3.
Draw the structure of
2,3-dimethylcyclopentanone.
6.
7.
Propose a mechanism for the reaction shown.
An unknown has the formula C4H6O and a strong peak in the IR spectrum near 1690 cm-1.
The 1H NMR spectrum is:
doublet,  2.0, 3H
multiplet,  6.1, 1H
multiplet,  6.9, 1H
doublet,  9.5, 1H
Give the structure of this unknown.