By Priyanka kalamkar

1. ALDOL
CONDENSATION
By Mrs. Priyanka Kalamkar
Asst Professor

2. ALDOL CONDENSATION
Key points
to
remember
ALDEHYDE
With α Hydrogen
KETONE
With α Hydrogen
Base Catalysed
Need OH- (NaOH/KOH)

3. What is ALPHA HYDROGEN ?

4. What is aldol condensation?
Aldehyde or ketone which has alpha
hydrogen reacts with any strong bases
such as NaOH to give aldol (β – Hydroxy
aldehyde or ketone) as the product.
Reaction doubles the number of carbon
atoms of initial aldehyde or ketone.

5. Acetaldehyde
β -Hydroxyacetaldehyde
(ALDOL)
-H2O
α , β –unsaturated
aldehyde
Aldol Reaction

6. Mechanism of
ALDOL
CONDENSATION

7. STEP 1 : Abstraction of α – Hydrogen and
formation of Carbanion
Carbanion
(Nucleophile is generated)Acetaldehyde

8. STEP 2 : Attack of Nucleophile on carbonyl C of another
molecule of Aldehyde and ketone
Alkoxide ion – Intermediate

9. STEP 3 : Protonation of Alkoxide ion
β -Hydroxyacetaldehyde
(ALDOL)

10. STEP 4 : Dehydration of Aldol
β -Hydroxyacetaldehyde
(ALDOL)
α , β –unsaturated
aldehyde

11. α , β –unsaturatedaldehyde ALDOL
Carbanion
Acetaldehyde
Another molecule
of Acetaldehyde

12. Which of the following will undergo
Aldol condensation and why ?
(a) Formaldehyde
(c) Benzaldehyde
(b) Propanal
(d) Acetone

13. Answer ……..

14. A]
B]
C]
D]
No α Carbon so
no α -hydrogen
α Carbon is there but
no α –hydrogen

15. Animated video of mechanism by Dr. Anwar Shaikh

16. CLASS WORK
Acetone NaOH
Predict the product of the following reaction with structure and
IUPAC Name(1M). Explain in detail with mechanism (2M).

17. Answer……
α
Carbon
β
Carbon
2
+ H2O

18. 1] Morrison and Boyd, organic chemistry, seventh
edition, (2011)
2] https://www.youtube.com/watch?v=Hfx3ln8KgsI
3] https://www.chemistryscl.com/reactions/aldol-
condensation/main.html