1: With tert.-butyl lithium in diethyl ether T=-78°C; 0.5 h; Inert atmosphere; 2: T=-78 - 20°C; 0.166667 h; Inert atmosphere;

1: With tert.-butyl lithium in diethyl ether; pentane T=-78°C; 2 h; 2: With Cu(II) pivalate in diethyl ether; pentane T=-60°C; 24 h;