We have demonstrated a new cyclobutane ring formation from the trans-1,2-disubstituted epoxides through intramolecular carbanion opening process. In this reaction, the nucleophilic carbanion is generated not via α-proton abstraction but via heteroconjugate addition. These studies indicate that the different configuration of each epoxide (syn and anti) do not affect its reactivity and the reaction velocity in the cyclization step, providing multifunctionalized cyclobutanes in a regio- and stereospecific manner.
- Heteroconjugate addition
- Sulfonyl carbanion