Treating the benzyl protected 3‐hydroxy‐1,3‐bis(2‐hydroxyphenyl)prop‐2‐en‐1‐ones solely with PhI(OAc)2 (PIDA) in DCE at room temperature readily furnished the seldom studied spiro‐2,2′‐benzo[b]furan‐3,3′‐ones in satisfactory to excellent yields. The hypervalent iodine reagent enables the metal‐free cascade spirocyclization resulting in the dual oxidative C−O bond formation.