$[Figure]$ $\xrightarrow[{Heat}]{{NaOC{H_3}\left( {1\,eq.} \right)}}$
[જ્યા $\left.Et = C _2 H _5\right]$
${C_2}{H_5}I\xrightarrow{{Alco.\,\,KOH}}X\xrightarrow{{B{r_2}}}Y\xrightarrow{{KCN}}Z$