Michael Reaction Definition:

A reaction in which a nucleophile attacks a conjugated p system, resulting in a 1,4-addition.

Michael Reaction Explained:

The base-catalyzed addition reaction between αα, BB – unsaturated carbonyl compounds cinnamaldehyde, benzylidene acetone, mesityl oxide, etc as a compound with the active methylene group is known as Michael addition. The base usually employed is sodium ethoxide or a secondary amine. Thus methyl vinyl ketone reacts with diethyl malonate in the presence of sodium ethoxide to give the addition product.