Question

The correct set of reagents which convert acetylene to but-$2$-enal are

• A. $H_{2}S{O}_4,NaOH$
• B. $H_{2}O/H{g}^{2+}/H^{+}$, dil $.NaOH$
• C. $H_{2}O/H^{+}$, conc $NaOH$
• D. $H_{2}O,KMn{O}_{4}O{H}^{-}$

Answer 1

Answer: (B)

Acetylene is $(HC\equiv CH)$, using $H_{2}O/H{g}^{2+}/H^{+}$dil. $NaOH$, we get but- $2$ -enal as follows.
$H_{3}C-HC=CH\to CHO$
$HC\equiv CH\stackrel{H_{2}O/H{g}^{2+}/H^{+},\text{dil}.NaOH}{\to }{H}_{3}C\to \underset{\text{but-2-enal <br/> (Product)}}{HC=CH\to CHO}$