Question

Dibenzyl ketone and benzil undergo an aldol condensation in base to make the reactant shown, which then undergoes a second aldol condensation to produce tetraphenylcyclopentadienone. complete the mechanism for an aldol condensation in base by drawing in the curved arrows where needed.

Answer 1

Step (1): Removal of acidic hydrogen leaving negative charge on carbon.
Step (2): Negative carbon attacking positive carbonyl carbon leads to formation of closed ring.
Step (3): Negative oxygen attracts proton from water regenerating the OH⁻ base.
Step (4): Dehydration and formation of double bond.