$(i)$ Glucose $+ ROH \quad \stackrel{\text { dry } HCl }{\longrightarrow}$ Acetal

$\xrightarrow[{{{\left( {C{H_3}CO} \right)}_2}O}]{{x\,eq.of}}$ acetyl derivative

$(ii)$ Glucose $\xrightarrow{{Ni/{H_2}}}A\xrightarrow[{{{\left( {C{H_3}CO} \right)}_2}O}]{{y\,\,eq.\,of}}$ acetyl derivative.

$(iii)$ Glucose $\xrightarrow[{{{\left( {C{H_3}CO} \right)}_2}O}]{{z\,ed.\,of}}$ acetyl derivative.

$' x ^{\prime},{ }^{\prime} y ^{\prime}$ and ${ }^{\prime} z^{\prime}$ in these reactions are respectively.