Double Elimination to Form Alkynes (NaNH₂): Mechanism + Exam Traps

Learn how vicinal/geminal dihalides form alkynes via two E2 eliminations with NaNH₂ — including terminal alkyne deprotonation and workup.

• Reaction: Double Elimination to Form Alkynes (NaNH₂)
• What it does: Learn how vicinal/geminal dihalides form alkynes via two E2 eliminations with NaNH₂ — including terminal alkyne deprotonation and workup.
• Typical reagents: 1) excess NaNH2, NH3(l) 2) H2O (or NH4Cl)
• Key intermediate: Phosphorus ylide / betaine
• Driving force: Formation of more stable bonds / products
• Exam type: Predict major product
• Exam type: Mechanism choice