potassium hydroxide; dihydrogen peroxide in methanol 2 h; Heating; Yield given;

1: potassium hydroxide; dihydrogen peroxide / water / 5 h / 2 - 50 °C 2: acetic anhydride / toluene / 7 h / 2 °C / |Inert atmosphere; |Reflux View Scheme

Stage #1: 1,3-dihydro-1-oxo-2H-indene With  sodium hydride in  DMF (N,N-dimethyl-formamide) T=0 - 20°C; 0.5 h; Stage #2: oxalic acid diethyl ester  in  DMF (N,N-dimethyl-formamide) T=0 - 20°C; 16 h;  Product distribution / selectivity;  Show Experimental Procedure  

With  sodium hydroxide T=30 - 40°C;