Johnson-Claisen · Orthoester [3,3] Shift
unseel.com · allylic alcohol → γ,δ-unsaturated ester · Johnson 1970
Stage assemble
Electrons 6 e⁻
Step allylic alcohol + orthoester
Oxygen
Carbon
Allyl C=C → product C=O
Ketene acetal C=C
New C-C bond
Unseel.com · Johnson-Claisen