1: With tert.-butyl lithium in diethyl ether; n-heptane; pentane T=-78°C; 0.25 h; 2: With methanol in diethyl ether; n-heptane; pentane T=-78 - 20°C; Further stages.;

sodium tert-pentoxide in toluene T=80°C;

1: With tert.-butyl lithium in n-heptane; anhydrous butyl ether T=-78°C; 2: With N,N,N',N,-tetramethylethylenediamine in n-heptane; anhydrous butyl ether T=-78 - 45°C; 3: With methanol in n-heptane; anhydrous butyl ether Further stages.;

1.1: KHMDS / tetrahydrofuran / 1 h / -78 °C 1.2: 46 percent / tetrahydrofuran / -78 - 20 °C 2.1: potassium tert-butoxide / tetrahydrofuran / 1 h / 20 °C 2.2: 44 percent / tetrahydrofuran / 7 h / 20 °C 3.1: t-BuLi / pentane; diethyl ether; heptane / 0.25 h / -78 °C 3.2: 95 percent / MeOH / pentane; diethyl ether; heptane / -78 - 20 °C View Scheme

1.1: potassium tert-butoxide / tetrahydrofuran / 1 h / 20 °C 1.2: 44 percent / tetrahydrofuran / 7 h / 20 °C 2.1: t-BuLi / pentane; diethyl ether; heptane / 0.25 h / -78 °C 2.2: 95 percent / MeOH / pentane; diethyl ether; heptane / -78 - 20 °C View Scheme

1.1: KHMDS / tetrahydrofuran / 1 h / -78 °C 1.2: 46 percent / tetrahydrofuran / -78 - 20 °C 2.1: potassium tert-butoxide / tetrahydrofuran / 1 h / 20 °C 2.2: 44 percent / tetrahydrofuran / 7 h / 20 °C 3.1: t-BuLi / pentane; diethyl ether; heptane / 0.25 h / -78 °C 3.2: 95 percent / MeOH / pentane; diethyl ether; heptane / -78 - 20 °C View Scheme

1: NaI / ethanol / 4 h / Heating 2: 95 percent / t-C5H11ONa / toluene / 80 °C View Scheme