The correct name of the reaction

is

CONCEPT:

Knoevenagel Reaction

• The Knoevenagel reaction is a base-catalyzed condensation reaction between an aldehyde (or ketone) and a compound containing an active methylene group (such as diethyl malonate).
• It typically results in the formation of an α,β-unsaturated compound through the elimination of water.
• In this reaction, the base deprotonates the methylene group, forming a carbanion, which then attacks the carbonyl carbon of the aldehyde.

EXPLANATION:

• In the given reaction, benzaldehyde (C₆H₅CHO) reacts with diethyl malonate (CH₂(COOC₂H₅)₂) in the presence of a base.
• The reaction forms an α,β-unsaturated diester as the product, which is a characteristic product of the Knoevenagel condensation.
• The other options are incorrect:
  • Wittig reaction: Forms alkenes using phosphonium ylides, not applicable here.
  • 
  • Aldol condensation: Involves carbonyl compounds reacting with each other, not an active methylene compound.
  • 
  • Cannizzaro reaction: Occurs in aldehydes without alpha hydrogens and involves oxidation-reduction, not observed here.
  • 

Therefore, the correct answer is Option 1: Knoevenagel reaction.