1: 47 percent / petroleum ether; tetrahydrofuran; hexane / 1.) -30 degC, 2.) heating to room temp. in 5h 2: 61 percent / tert-C4H9Li / tetrahydrofuran; pentane / 2 h / Heating; also with (iso-C3H7)2NLi in THF/hexane View Scheme