Question

What do you understand by these following terms? Give one example of each.
(i) Aldol (ii) Schiff's base (iii) Cannizaro's reaction (iv) Oxime (v) Acetal

Hint:

Aldol reactions involve the formation of β-hydroxy aldehydes or ketones and are catalyzed by either a base or acid.

Answer 1

(i) Aldol
An Aldol reaction is a type of organic reaction where an enolate ion (or sometimes an aldehyde or ketone) reacts with a carbonyl compound to form a β-hydroxy aldehyde or ketone, also called an aldol. The reaction occurs due to the nucleophilic attack of the enolate or aldehyde carbonyl carbon. The general form of the aldol reaction is: \[ \text{RCHO + R'CHO} \rightarrow \text{RCH(OH)CH(R')CHO} \] Example: The reaction between acetaldehyde (CH₃CHO) and acetaldehyde gives 4-hydroxybutanal (a β-hydroxy aldehyde), which is an aldol addition product.