In an adol reaction why doesn't the dibenzalacetone product react with the excess benzaladehyde in mixture?

Question

In an adol reaction why doesn't the dibenzalacetone product react with the excess benzaladehyde in mixture?

Answer 1

Because dibenzalacetone cannot generate an enolate. Dibenzalacetone is the double dehydration product formed from 1 eq of acetone and 2 eq of benzaldehyde. It's structure is as follows...

C6H5-CH=CH-CO-CH=CH-C6H5...

It is a bis-alpha,beta-unsaturated ketone and cannot enolize. If anything, it is an electrophile that can undergo 1,2- (at the carbonyl carbon) or 1,4- (at the beta carbon) addition