1.1: 2,2,6,6-tetramethylpiperidine; potassium tert-butoxide; N,N,N',N'',N''-pentamethylenediamine / butyllithium / tetrahydrofuran; hexane / 0.75 h / -125 °C 1.2: tetrahydrofuran; hexane 2.1: HCl / H2O 3.1: 1.92 g / NaOH; zinc powder / H2O / 2 h / 25 °C View Scheme