1: n-butyllithium; bromobenzene in diethyl ether; hexane T=-70 - 20°C; 1 h; Inert atmosphere; 2: 1,1,3,3-tetramethyl-indan-2-carboxylic acid in diethyl ether; hexane T=20°C; 24 h; Inert atmosphere; 3: carbon dioxide in diethyl ether; hexane Heating;

1: para-bromotoluene With tert.-butyl lithium in diethyl ether T=-78°C; 0.5 h; Inert atmosphere; 2: 1,1,3,3-tetramethyl-indan-2-carboxylic acid in diethyl ether T=20°C; 18 h; Inert atmosphere; 3: carbon dioxide in diethyl ether Heating;

1.1: n-butyllithium / -70 - 20 °C 1.2: 6 h / 40 °C / |Inert atmosphere 2.1: 2,2,2-tribromo-2,2-dihydrobenzo-1,3,2-dioxaphosphole / dichloromethane / 47 °C / |Inert atmosphere View Scheme

1: n-butyllithium; bromobenzene in diethyl ether; hexane T=-70 - 20°C; 1 h; Inert atmosphere; 2: 1,1,3,3-tetramethyl-indan-2-carboxylic acid in diethyl ether; hexane T=20°C; 24 h; Inert atmosphere; 3: carbon dioxide in diethyl ether; hexane Heating;