Question

Identify (X), (Y) and (Z) reagents in the given sequence of reaction. $CH\equiv CH\stackrel{X}{\to }C{H}_{3}CHO\stackrel{Y}{\to }C{H}_{3}CH\left(OH\right)C{H}_3\stackrel{Z}{\to }C{H}_{3}COC{H}_3$

• A. $X=H_{2}S{O}_4$, $Y=H_3{O}^{+}$, $Z=PC{l}_5,\text{heat}$
• B. $X=HN{O}_3$, $Y=N{a}_{2}C{O}_3$, $Z=H_{2}S{O}_4$
• C. $X=H_{2}S{O}_4/H{g}^{2+}$, $Y=PC{l}_5/H_{2}O$, $Z=K_{2}C{r}_2{O}_7/O{H}^{-}$
• D. $X=H_{2}S{O}_4/H{g}^{2+},$ $Y=C{H}_{3}MgBr/H_{2}O,$ $Z=K_{2}C{r}_2{O}_7/H^{+}$

Answer 1

The correct option is D $X=H_{2}S{O}_4/H{g}^{2+},$ $Y=C{H}_{3}MgBr/H_{2}O,$ $Z=K_{2}C{r}_2{O}_7/H^{+}$

Alkynes react with water in the presence of dilute sulphuric acid and mercuric sulphate at a temperature of $333K.$ This results in the formation of carbonyl compounds through a keto-enol tautomerization of the more substituted enol. ( except for acetylene which yields acetaldehyde ).

Grignard reagent is a strong nucleophile. It undergoes nucleophilic addition reaction when it reacts with aldehyde, ester and ketone.
Grignard reagent react with formaldehyde to form $1^{\circ }$ alcohol.
Grignard reagent react with aldehyde except formaldehyde to form $2^{\circ }$ alcohol.
$K_{2}C{r}_2{O}_7/H^{+}$ oxidizes $2^o$ alcohol into ketone.
$CH\equiv CH\underset{H{g}^{2+}}{\overset{H_{2}S{O}_4}{\to }}C{H}_{3}CHO\stackrel{C{H}_{3}MgBr/H_{2}O}{\to }C{H}_{3}CH\left(OH\right)C{H}_3\stackrel{K_{2}C{r}_2{O}_7/H^{+}}{\to }C{H}_{3}COC{H}_3$