Consider the following sequence of reactions:
Ketone $A$ $\xrightarrow[2. H_2O]{1. C_2H_5MgBr} B$ $\xrightarrow[- H_2O]{H_2SO_4, \text{Heat}} C$ $\xrightarrow[2. Zn, H_2O]{1. O_3} \text{Propanone} + \text{Acetaldehyde}$
The ketone $A$ is:

Which one of the following aldehydes will not form an aldol when treated with $dil. \, NaOH$?

An optically active alkyl bromide $C_4H_9Br$ reacts with ethanolic $KOH$ to form major compound $[A]$, which reacts with bromine to give compound $[B]$. Compound $[B]$ reacts with ethanolic $KOH$ and sodamide to give compound $[C]$. One molecule of water adds to compound $[C]$ on warming with mercuric sulphate and dilute sulphuric acid at $333 \text{ K}$ to form compound $[D]$. The functional group in compound $[D]$ will be confirmed by:

Compound $(X)$ undergoes the following sequence of reactions to give the Lactone $(Y)$. Identify $(X)$.

How can benzyl alcohol be obtained from benzaldehyde?

$CH_3-CH_2-OH$ $\xrightarrow{PCC} A$ $\xrightarrow{HCN} B$ $\xrightarrow[\Delta]{H_3O^{+}} C$
Compound $C$ is: