1: With tert.-butyl lithium in tetrahydrofuran; water T=-78°C; 0.583333 h; 2: With boric acid trimethyl ester in tetrahydrofuran T=0°C; 2 h; 3: With potassium hydrogensulfate; sulfuric acid; ammonium chloride more than 3 stages;

1: 6-(tert-butyldimethylsilanyloxy)indole-1-carboxylic acid tert-butyl ester With tert.-butyl lithium in tetrahydrofuran; pentane T=-78°C; 1.16667 h; 2: boric acid trimethyl ester in tetrahydrofuran; pentane T=0°C; 2 h;