Question

Predict the initial and final products for the following reaction involving 2-pentyne. Hint: the products are isomers and in equilibrium with each other.
2-pentyne with catalyst of H2O, H2SO4, HgSO4

Answer 1

Answer:

Structure of both products are given below.

Explanation:

• This reaction is an example of oxymercuration reaction of double bond.
• Here $Hg^{2+}$ ion makes coordination with double bond in first step resulting formation of a complex having transient carbocationic character.
• In the second step, a water molecule attacks the above complex at more substituted position and forms an enol (initial product) subsequently.
• Enol is being tautomerized and converted to a ketone (final product)
• Full mechanism has been shown below.