Identify the Carbonyl compound which will not be formed when hydration of Alkynes is carried out with dil. H ₂ SO ₄ / Hg ²⁺ at 333 K . Acetone, Butanal, Ethanal, Butanone.

Step-by-step solution

Hydration of alkynes in the presence of dil. H ₂ SO ₄ and Hg ²⁺ follows Markovnikov addition of water to the triple bond, forming an enol intermediate which tautomerizes to a carbonyl compound. For ethyne ( HC CH ), hydration yields ethenol, which tautomerizes to ethanal ( CH₃CHO ). For propyne ( CH₃C CH ), hydration yields prop-1-en-2-ol, which tautomerizes to acetone ( CH₃COCH₃ ). For but-1-yne ( CH₃CH₂C CH ), hydration yields but-1-en-2-ol, which tautomerizes to butanone ( CH₃COCH₂CH₃ ). For but-2-yne ( CH₃C CCH