question archive The product is probably (##2E,5E##)-2,5-bis(4-methylbenzylidene)cyclopentanone
The product is probably (##2E,5E##)-2,5-bis(4-methylbenzylidene)cyclopentanone
Subject:ChemistryPrice: Bought3
The product is probably (##2E,5E##)-2,5-bis(4-methylbenzylidene)cyclopentanone.
The aldol condensation involves attack of an enolate ion on the base of a carbonyl compound to form a β-hydroxycarbonyl compound (an aldol).
(from www.chem.ucla.edu)
The aldol can then dehydrate to form an α,β-unsaturated carbonyl compound.
The process requires an active methylene adjacent to a carbonyl group.
If there are two active methylenes, the condensation can occur on each side of the carbonyl group.
For example, benzaldehyde with acetone gives dibenzalacetone.
By analogy, I predict that 4-methylbenzaldehyde with cyclopentanone will form (##2E,5E##)-2,5-bis(4-methylbenzylidene)cyclopentanone.
The ##E,E## isomer should be more stable because the steric interactions of the ortho hydrogens with the ##"H"## atoms on the cyclopentane ring are smaller than those with the carbonyl oxygen
