Noun
Knoevenagel condensation (countable and uncountable, plural Knoevenagel condensations)
(organic chemistry) The nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule of water is eliminated. The product is often an α,β-unsaturated ketone (a conjugated enone).
Synonym: Knoevenagel reaction
First, acrolein is formed in a Knoevenagel condensation from the acetaldehyde and formaldehyde. Source: Internet