Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as:
Aldol condensation occurs in aldehydes having α-hydrogen with a dilute base to give β-hydroxy aldehydes called aldols. This reaction is most commonly known as aldol condensation. If the condensation reaction occurs between two different carbonyl compounds it is called crossed aldol condensation.
Acetophenone has α−H and while benzaldehyde do not have α−H hence give cross-aldol reaction in presence of dil NaOH.
Here acetophenone reacts with NaOH and form a nucleophile which reacts with benzaldehyde. It is known as cross aldol reaction.
C6H5CHO+CH3COC6H5NaOH→−H2OC6H5−CH=CH−COC6H5
Hence, (b) is the correct option.