1: indole carboxylic acid ester With tert.-butyl lithium in tetrahydrofuran; hexane T=-78°C; 2 h; 2: indan-2-one in tetrahydrofuran 2 h;

in tetrahydrofuran T=-72°C;

1.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: tetrahydrofuran / 0.17 h 2.1: t-butyllithium / tetrahydrofuran; hexane / 2 h / -78 °C 2.2: 11.5 g / tetrahydrofuran / 2 h View Scheme