The document discusses aldol condensation, an organic reaction where two molecules of an aldehyde or ketone undergo a condensation reaction in the presence of a base to yield a β–hydroxyaldehyde or β–hydroxyketone. It involves the reaction of an enolate ion, formed from deprotonation of an aldehyde, with a carbonyl compound to form an aldol. This may then undergo dehydration to form a conjugated enone. The mechanism proceeds through enolate formation, carbon-carbon bond formation between the enolate and carbonyl, and protonation to form the aldol intermediate. Crossed aldol condensation refers to the reaction between two different aldehyde or ketone

1. ALDOL CONDENSATION
PRESENTED BY: MR K V NANDA KUMAR
ASSOCIATE PROFESSOR
KRISHNA TEJA PHARMACY COLLEGE, TIRUPATHI-517506
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2. Aldol Condensation
The aldol condensation reaction is an organic reaction introduced by Charles Wurtz, who first
prepared the β-hydroxy aldehyde from acetaldehdye in 1872.
Two molecules of an aldehyde or a ketone undergo a condensation reaction in the presence
of a base to yield β – hydroxyaldehyde or β – hydroxyketone.
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3. Aldols
An aldol or aldol adduct (from "aldehyde alcohol") is a
hydroxy ketone or aldehyde, and is the product of aldol
addition (as opposed to aldol condensation, which
produces an α,β-unsaturated carbonyl moiety).
When used alone, the term "aldol" may also refer
specifically to the compound 3-hydroxybutanal
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4. General Aldol Condensation Reaction
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 Aldol Condensation can be defined as an organic reaction in which enolate
ion reacts with a carbonyl compound to form β-hydroxy ketone or β-hydroxy
aldehyde, followed by dehydration to give a conjugated enone.
 Aldol Condensation plays a vital role in organic synthesis, creating a path to
form carbon-carbon bonds.

5. Mechanism of aldol condensation
Step 1:
In reverse order, the hydroxide ion deprotonates the aldehyde.
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Aldehyde Enolate ionHydroxide ion Water

6. Mechanism of aldol condensation
Step 2:
Here Enolate ion 1 adds to the unreacted aldehyde.
.
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Unreacted
Aldehyde
Enolate ion Alkoxide ion

7. Mechanism of aldol condensation
Step 3:
Alkoxide ion 2 is protonated by water.
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Alkoxide ion Water Aldol Hydroxide ion

8. Mechanism of aldol condensation
Step 4:
A small amount of aldol is converted into enolate ion (4) by hydroxide ion.
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Aldol Hydroxide ion Enolate ion Water

9. Mechanism of aldol condensation
Step 5:
Here Enolate Ion(4) loses a hydroxide ion.
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Step 1 to step 3 illustrates the aldol reaction.

10. Crossed aldol condensation
The condensation reaction between two different molecules of an aldehyde or ketone in a
protic solvent such as water or alcohol constitutes the crossed aldol reaction.
When condensation is between two different carbonyl compounds, it is called crossed aldol
condensation.
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11. Questions
1. What is aldol condensation?
2. Give one example for aldol condensation reaction.
3. Explain the mechanism of aldol condensation.
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