what is mechanism of aldol reaction?????

* The first step in base catalyzed aldol reaction is the abstraction of an a-hydrogen from the enolizable carbonyl compound to give aresonancestabilized enolate anion. Usually this step is slow and rate determining.Note: Usually hydroxide ion is used as a base, since it is less basic than the enolate ion. This ensures the formation of only small amount of enolate ion and is a necessary condition for further reaction of this ion with unionized carbonyl compound. Otherwise, if strong bases like amide are used, all the reactant molecules are converted to enolate ions and no further addition is possible.

*The next step is the nucleophilic addition of enolate anion to the carbonyl group of second aldehyde or ketone molecule. The final product formed after protic workup is aß-hydroxy carbonylcompound (an aldol)