Claisen Rearrangement: [3,3]-Sigmatropic Shift (Allyl Vinyl/Aryl Ethers → Carbonyl Products)

Learn the Claisen rearrangement: concerted [3,3] shift, chair transition state, and why it's stereospecific. Predict products for allyl vinyl/aryl ethers.

• Reaction: Allyl vinyl ether → γ,δ-unsaturated carbonyl (after tautomerization)
• What it does: Rearranges allyl ethers via pericyclic shift
• Typical reagents: Heat
• Key intermediate: None (concerted transition state)
• Driving force: Formation of new C–C bond; tautomerization to carbonyl
• Exam type: Pericyclic
• Exam type: Stereospecificity