The major product in the following reaction is

The major product of the following reaction is

The products $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ in the following reaction sequence are

Identify $\mathrm{X}$ and $\mathrm{Y}$ in the following reactions

$\mathrm{R}-\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_2\mathrm{OH}\stackrel{\mathrm{X}}{\to }\mathrm{R}-\mathrm{CH}=\mathrm{CH}-\mathrm{CHO}$
$\mathrm{R}-{\mathrm{CH}}_2\mathrm{OH}\stackrel{\mathrm{Y}}{⟶}\mathrm{R}-\mathrm{COOH}$

Identify $"\mathrm{Z}"$ in the following series of reaction

$\mathrm{Butan}-2-\mathrm{ol}\stackrel{{\mathrm{PCl}}_3}{⟶}\mathrm{X}\stackrel{ \mathrm{alco}.\mathrm{KOH} }{⟶}\mathrm{Y}\underset{\mathrm{ii})\mathrm{H}-\mathrm{OH}/\mathrm{heat} }{\overset{ \mathrm{i}) {\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}\mathrm{Z}$

Which is the most suitable reagent for the following transformation?