potassium carbonate in acetone 2 h; Heating / reflux;

1: With n-butyllithium in tetrahydrofuran; hexanes T=-100 - -78°C; 1.33333 h; Cooling with diethyl ether/liquid nitrogenCooling with acetone/Drikold; 2: With tri-isopropoxy-borane in tetrahydrofuran; hexanes T=-78 - 20°C; 1.5 h; Cooling with acetone/Drikold;