Base Mediated Formal [2+4] Annulation of 3‐Hydroxyoxindoles with 1,2‐Bis(bromomethyl)benzene: Access to Spirooxindole‐Fused Oxacycles

Abstract Here a base‐mediated formal [2+4] annulation of 3‐hydroxyoxindoles with 1,2‐bis(bromomethyl)benzene have been accomplished, affording spirooxindole‐fused oxacycles in good yields. This protocol features great functional group tolerance in mild reaction conditions. Gram‐scale synthesis and further transformation have also been demonstrated.