1: 87 percent / carbonyldiimidazole / CH2Cl2 2: diethyl ether / 20 °C View Scheme

water T=300°C; 1 h;

potassium hydroxide in methanol; water 18 h; Ambient temperature;

1: 80 percent / NaH / diethyl ether 2: 91 percent / K2CO3 / methanol; H2O View Scheme

sodium hydroxide in methanol T=50°C; 3 h;

n-butyllithium 1.) THF, hexane, 0 deg C, 20 min, 2.) -78 deg C, 12 h; Multistep reaction;

1: Et3N / tetrahydrofuran / 1 h / Ambient temperature 2: tetrahydrofuran / 3 h / Ambient temperature 3: 95 percent / 4 N H2SO4 / tetrahydrofuran / 4 h / Heating 4: 81 percent / LiAlH4 / diethyl ether 5: 1.) Et3N / 1.) CH2Cl2, 10 min, 2.) CH2Cl2, RT, 1 h 6: 62 percent / 15-crown-5 / dimethylsulfoxide / Ambient temperature 7: 83 percent / i-Bu2AlH / benzene; hexane / 3 h / 0 °C 8: 76 percent / CrO3, aq. H2SO4 / acetone / 0.5 h / Ambient temperature View Scheme

in diethyl ether

1: (+/-)-methylenecyclopropanecarboxylic acid With triethylamine; isobutyl chloroformate in tetrahydrofuran T=0°C; 0.25 h; 2: diethylamine in tetrahydrofuran T=20°C; 12 h; Further stages.;

1: 87 percent / carbonyldiimidazole / CH2Cl2 2: diethyl ether / 4 h / 20 °C View Scheme