Alkyne Hydration (HgSO₄): Markovnikov Water Addition → Ketones

Master mercuric-ion catalyzed hydration of alkynes. Markovnikov addition, enol formation, keto-enol tautomerization, and common pitfalls.

• Reaction: Alkyne + H2O → ketone (via enol)
• What it does: Hydrates alkynes to give ketones (terminal alkynes give methyl ketones)
• Typical reagents: HgSO4, H2SO4, H2O
• Key intermediate: Vinyl mercurinium / vinyl cation-like intermediate; enol
• Driving force: Tautomerization to more stable ketone
• Exam type: Regiochemistry
• Exam type: Tautomerization
• Exam type: Predict product