Question

How many different alkynes, on treatment with $HgS{O}_4/H_{2}S{O}_4$ can give 2-pentanone as one of the product?

Answer 1

$\text{Structure of}2\text{-pentanone}$

$\begin{array}{c}{HgSO}_4/H_2{SO}_4\text{is used for hydrolysis of alkynes. To form}\\ \text{enol's they undergo tautomerism to form keto structures,}\\ \text{Possible enols are:}\end{array}$

$\text{So the possible alkynes are}$

$\text{So, number of alkynes are two.}$