1: toluene With n-butyllithium; potassium tert-butylate 2: 2-(dichloromethylidene)-1,1,3,3-tetramethylindane in tetrahydrofuran T=20°C; 0.5 h; Inert atmosphere; 3: carbon dioxide in tetrahydrofuran Heating;

potassium hydroxide T=100°C; 6 h; Inert atmosphere; Mechanism; Reagent/catalystTemperature;

potassium hydroxide T=100°C; 6 h; Inert atmosphere; Mechanism; Reagent/catalystTemperature;