${C_2}{H_5}I\xrightarrow{{alc. KOH}}X\xrightarrow[{CC{l_4}}]{{B{r_2}}}Y\,\xrightarrow{{KCN}}Z\xrightarrow{{{H_3}{O^ + }}}A$
સક્સીનીક એસિડ

$(a)$ $PhCOOH$
$(B)$ $o-NO_2C_6H_4COOH$
$(C)$ $p-NO_2C_6H_4COOH$
$(D)$ $m-NO_2C_6H_4COOH$
$C{H_2}CN\xrightarrow{{Na/{C_2}{H_5}OH}}\,A\,\xrightarrow{{HN{O_2}}}\,B\,\xrightarrow{{C{r_2}O_{_7}^{ - 2}}}\,C$



$C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}Br\xrightarrow{NaCN}$ $X\xrightarrow[heat]{{{H}_{3}}{{O}^{+}}}Y\xrightarrow[{{H}^{+}}]{C{{H}_{3}}C{{H}_{2}}OH}Z$