Answer:
(CH3)3CCHO
Explanation:
Carbonyl compounds that contain alpha hydrogen atoms are the only ones that can undergo aldol condensation reaction.
Aldol condensation is one of the condensation reactions in organic chemistry that occurs when an enol or an enolate ion reacts with another carbonyl compound to yield a β-hydroxyaldehyde or β-hydroxyketone, this is immediately followed by the dehydration of the product to yield a conjugated enone.
(CH3)3CCHO lacks alpha hydrogen atoms hence it does not undergo the aldol condensation.