Consider the above reaction sequence and identify the product $B$.

The reaction shown in the image is called:

For the given compound,determine the number of hydrogen atoms that are replaced by $D$ upon keeping it for a long time with $\mathop O\limits^\ominus D / D_2O$.

In the following conversion,
$C_6H_5CN$ $\xrightarrow[(ii) H_3O^+]{(i) MeMgBr} X$ $\xrightarrow[H_3O^+]{NaOH/I_2} Y$
the major products $X$ and $Y$,respectively are

The correct order of reactivity of $CH_3CHO$,$C_2H_5COCH_3$,and $CH_3COCH_3$ towards nucleophilic addition is:

Which of the following carbonyl compounds does $NOT$ undergo aldol condensation?