1: acetonitrile With lithium diisopropyl amide in tetrahydrofuran; hexane T=-10°C; 0.5 h; 2: isobutyraldehyde in tetrahydrofuran; hexane T=-10°C; 1 h; Further stages.;

[(Me)PNP(i-Pr)]NiOTf; 1,8-diazabicyclo[5.4.0]undec-7-ene T=45°C; 72 h;