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Q.
The carbonyl compound that does not undergo aldol condensation is
KCETKCET 2020Aldehydes Ketones and Carboxylic Acids
Solution:
At least one $\alpha$-hydrogen should be present for an aldehyde or a ketone to undergo aldol reaction. The only compound that does not have even one $\alpha$-hydrogen is trichloroacetaldehyde, and hence, it does not undergo aldol reaction.