Answers: Among many few compounds are shown below which can not undergo Aldol Condensation reactions.
Explanation: Aldol Condensation reactions are given by those carbonyl compounds which are capable of forming conjugate bases called as
Enolates. Enolates are formed when carbonyl compounds having hydrogen atoms at
alpha position are treated with
strong bases. This hydrogen atom at alpha position is
mildly acidic in nature and readily donated to base as the upcoming conjugate base i.e. has
stability due to resonance.
So those carbonyl compounds which
lacks these acidic protons at alpha position are not able to form enolates, Hence, unable to undergo Aldol Condensation reactions. Few examples are attached below,