Methylene and arylidene bisnaphthols can be converted into 4,5,2’,3’‐dibenzo‐3‐grisa‐2’,4’‐dien‐6’‐ones under catalytic conditions in the presence of copper(II)‐tetramethylethylenediamine [CuCl(OH)(TMEDA)]2. The reaction simply proceeds under air at room temperature and the control of stereoselectivity is total, affording the only (RR+SS) diastereoisomer.