Chpt 18 Ketones

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Chpt 18 - Ketones Aldehydes
Reactivity
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• Nomenclature
• 1. Common names

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2. IUPAC names a. ketones - in parent alkane
drop e and add one. Number position of the
carbonyl carbon as low as possible (in a cyclic
molecule this is always carbon - 1). As a
substituent one can name O as an oxo
group. Examples
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b. aldehydes- drop the final e of the alkane
name and add al As a sustituent -C(O)H is a
formyl group Examples

• Remember priority rules for substituents
• 1. Carboxylic Acids
• 2. Esters
• 3. Amides
• 4. Nitriles
• 5. Aldehydes
• 6. Ketones
• 7. Alcohols
• 8. Amines

(see back of your book!)
9. Alkenes 10. Alkynes 11. Alkanes 12. Ethers 13.
Halides
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B. Physical Properties
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C. Industrial Uses
Most common is that of a solvent
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D. Spectroscopic Properties 1. IR - CO stretch
- intense- from 1780-1650 cm-1 C-H stretch in
aldehydes 2710 cm-1 and 2810 cm-1 2. 1H NMR
R-C(O)-H
d 9-10ppm
2.13C NMR
-C(O)-
d 190 - 210 ppm
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E. Synthesis - a review(!) 1. oxidation
Note PCC
2. ozonolysis mild reduction
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3. Friedal-Crafts acylation (17-11)
-or-
Gatterman-Koch synthesis
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4. oxymercuration
5. borohydride addition and oxidation
And now on to more (and new) synthetic
pathways!!
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F. Alkylation and hydrolysis of 1,3-dithianes
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G. Alkylation of carboxylic acids and hydrolysis
A partial mechanism
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H. Alkylation of nitriles and hydrolysis
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• Reactions of acid chlorides
• 1. reduction to aldehydes - normally

BUT, with sterically bulky reagents we can
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We can also do the Rosemund reduction
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2. Conversion to ketones - normally -
BUT, using less reactive organocuprates
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J. Reactions of aldehydes and ketones - general
principles There are three sites of reactivity
We will see the reactivity patterns leading from
this feature in Chpt 22.
Recall that CO is polarized
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So a general pattern is for nucleophiles to react
at the carbonyl carbon -
WEAK nucleophiles can be added by activating the
CO group - protonating the carbonyl
oxygen -
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So
We will see a million of these reactions!!!

Reactions to review
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K. The Wittig Reaction 1. overall reaction
phosphorus ylide
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2. formation of phosphorus ylide
3. mechanism
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4. examples
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L. Hydrolysis of ketones and aldehydes 1.
general reaction
2. position of equilibrium - general
considerations
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3. mechanism a. acid catalyzed
(we just saw this before)
b. base catalyzed
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M. Formation of acetals and ketals - using R-OH
instead of H-OH

• Hemiacetal/hemiketal formation
• a. general equilibrium conditions

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b. general mechanism
(we saw before)
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c. cyclic hemiacetals
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2. acetal/ketal formation - more favorable
equilbrium in general the basic mechanism is (for
acid catalyzed)
And now,
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3. protecting groups..
distilled off
Use in Grignard reagent or Wittig reagent
synthesis, etc.
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N. Formation of cyanohydrins
You probably dont want to do the acid catalyzed
reaction
Cyanohydrins can be hydrolyzed
?-hydroxycarboxylic acids
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O. Formation of imines 1. overall reaction
2. some examples
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NOTE Amine must have two hydrogens, i.e.
R-NH2
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3. mechanism
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P. Reductions of ketones and aldehydes
1. Raney Ni
overall like 1)LiAlH4 2)H3O
2. Wolf-Kishner Clemenson reductions
Note highly acidic conditions
Note highly basic conditions
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A couple of examples
Q. Summary 1. Nomenclature 2. IR/1H NMR/ 13C
NMR
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3. Synthesis a. review i. oxidation of
alcohols ii. ozonolysis reduction iii.
Friedal-Crafts acylation iv. Gattermaan-Koch
synthesis v. oxymercuration/demercuration of
alkynes vi. borohydride addition oxidation of
alkynes b. new reactions i. alkylation
hydrolysis of 1,3-dithianes ii. alkylation of
carboxylic acids - partial mech iii. alkylation
hydrolysis of nitriles iv. reduction of acid
chlorides - Rosemund reaction v. alkylation of
acid chlorides 4. Reactions of aldehydes and
ketones -review a. Grignard synthesis b.
hydride reductions
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5. New reactions of aldehydes and ketones a.
Wittig reaction i. preparation of phosphorus
ylides ii. mechanism b. reaction with H2O
ROH i. overall patterns - equilibria ii.
mechanisms acid base catalyzed iii.
synthetic uses of acetals c. imine formation -
mechanism d. cyanohydrin formation - mechanism
hydrolysis e. reductions i. Raney Ni ii.
Clemenson (acidic conditions) iii. Wolf-Kishner
(basic conditions)
Note for now we are skipping Chapter 19 Amines