Write a note a 'aldol condensation'

Explanation

Aldol condensation : Two molecules of a suitable aldehyde or ketone under the influence of dilute alkali combine to from a `beta-`hydroxyldehydr or `beta-`hydroxyketon. For example
`underset("Ethanal")(CH_(3)CHO)+underset("Ethanal")(HCH_(2)CHO)underset(":"OH^(-))overset(Ca(OH)_(2))tounderset(("Acetaldol"))underset("3-hydroxybutanal")(CH_(3)CH(OH)CH_(2)CHO)`
This reaction is called aldon condensation as the product (3- hydroxy butanal) contains both a hydroxyl group and an aldehydr group.
Similar condensation of two molecules of ketones is also designated as aldol condensation although the product in that case contains keto rather than aldehyde group. For example
`underset("Propanone")(CH_(3)COCH_(3))+underset("Propanone")(CH_(3)COCH_(3))overset(Θ)overset(":"OH)to`
`{:(" "OH),(" "|),((CH_(3))_(2)C CH_(2)COCH_(3)),("4- Hydroxy-4-methyl 2-pentanone"),(" "("Diacetonyl alcohol")):}`
Mechanism :

(ii)
ltBRgt (iii) `H_(3)C-underset(CH_(2)CHO)underset(|)overset(O^(-))overset(|)C-H +H_(2)OhArrH_(3)C -underset("Aletalodal")underset(CH_(2)CHO)underset(|)overset(OH)overset(|)C-H+underset(* *)overset(Θ)(":"OH)`