1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran 0.25 h; Ambient temperature;

Ni(trans,trans,trans-1,5,9-cyclododecatriene); N,N,N',N,-tetramethylethylenediamine 1.) THF, from -78 deg C to -15 deg C, 5 h, 2.) THF, 20 deg C, 24 h, 1 bar; Yield given. Multistep reaction;