bis(1,5-cyclooctadiene)nickel (0) in N,N-dimethyl-formamide 1.) - 78 deg C, 2.) 25 deg C, 10 min, 3.) 35 deg C, 12 h;

silica gel; pyridinium chlorochromate in dichloromethane T=20°C; 2 h; Inert atmosphere;

1: 95 percent / tetrahydrofuran / 1.) 0 deg C, 1.5 h 2.) room temp., 3 h 2: 83 percent / pyridinium dichromate / dimethylformamide / 1.) 0 deg C, 5 h 2.) room temp., 7 h View Scheme