sodium hydroxide in ethanol; water T=60°C;

1: With lithium triethylborohydride in tetrahydrofuran T=-78 - 20°C; 19 h; 2: With water in tetrahydrofuran 2 h; Heating; 3: With sodium hydroxide; dihydrogen peroxide in tetrahydrofuran T=20°C; 1 h;

1.1: NiBr2*3H2O; 1,2-dibromoethane; pyridine / tetrabutylammonium iodide; tetrabutylammonium bromide / dimethylformamide / 80 °C / Electrochemical reaction 1.2: 23 percent / aq. HCl / dimethylformamide 2.1: 75 percent / NiCl2; NaBH4 / methanol / 3 h / 20 °C View Scheme

tetra-(n-butyl)ammonium iodide; ethylene dibromide; niobium bromide; tetra-(n-butyl)ammonium iodide in N,N-dimethyl-formamide; acetonitrile T=80°C; Electrochemical reaction;

hydrogenchloride; diisobutylaluminium hydride in water; toluene

1: With pyridine; ethylene dibromide; niobium bromide; tetrabutylammomium bromide; tetra-(n-butyl)ammonium iodide in N,N-dimethyl-formamide T=80°C; Electrochemical reaction; 2: With hydrogenchloride in N,N-dimethyl-formamide