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Q.
$A \xrightarrow{HCl} (CH_3)_3C = CHCOCH_3, $ A is
MHT CETMHT CET 2004Aldehydes Ketones and Carboxylic Acids
Solution:
Acetone $(CH_3COCH_3)$ undergoes condensation reaction in
presence of HCI to produce mesityl oxide.
$\underset{A}{2CH_3COCH_3} \xrightarrow[-H_2O]{HCI} \underset{4-methyl \, pent-3-en-2-one \
or \, mesityl \, oxide }{(CH_3)_2 - C = CHCOCH_3} $