1: diazomethyl-trimethyl-silane With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1 h; 2: pentanal With methanol in tetrahydrofuran; hexane T=-78°C; 0.833333 h; 3: With dirhodium tetraacetate in tetrahydrofuran; hexane T=-78 - 20°C; Further stages.;

lithium diisopropyl amide 1.) THF, -78 deg C, 30 min, 2.) THF, from -78 deg C to RT; Yield given. Multistep reaction;

magnesium; ethylene dibromide 1.) THF, reflux, 6 h; 2.) THF, diethyl ether, room temperature, 1 h; Yield given. Multistep reaction;