1: With N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78°C; 1 h; Inert atmosphere; 2: With 3,4,5,6-tetrachloro-1,2-benzoquinone; acetic acid in tetrahydrofuran; cyclohexane T=-78 - 20°C; Inert atmosphere; chemoselective reaction;