Stereocontrolled [4+1] Annulation of α‐Hydroxycyclobutenones: Synthesis of Polysubstituted Cyclopentenones

Abstract A stereocontrolled [4+1] annulation of α‐hydroxycyclobutenones has been disclosed. For the first time, α‐hydroxycyclobutenones have been proven as facile diene precursors for [4+1] annulation. Meanwhile, the reported transformation presents a concise synthetic route to polysubstituted cyclopentenones with high stereoselectivity. magnified image