The compound $(x)$ in the above reaction is:

Give the conversion of the following:
$(i)$ $but-2-enal$ from $ethanal$
$(ii)$ $Methyl$ $benzoate$ from $benzaldehyde$

In the following sequence of reactions,compound $M$ is:
$M$ $\xrightarrow{CH_3MgBr} N + CH_4 \uparrow$ $\xrightarrow{H^+} CH_3COCH_2COCH_3$

Formaldehyde reacts with ammonia to give urotropine. The formula of urotropine is

What is $\underline{Z}$ in the following sequence of reactions?

Identify the compounds $A$ and $B$ involved in the formation of the given aldol product: $A + B \xrightarrow{OH^-} CH_3-CH_2-CH(OH)-CH(CH_3)-CHO$