Complete oxidation of organic compound $\mathrm{A}$ with ${\mathrm{Na}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ and ${\mathrm{H}}_2{\mathrm{SO}}_4$ gives compound $\mathrm{B},$ which on reduction with ${\mathrm{H}}_2$ in the presence of $\mathrm{Ni}$ catalyst gives ethyl alcohol. Give the name of compound $\mathrm{A}.$