1: ethyl α,α-dibromocaproate With tert.-butyl lithium in tetrahydrofuran; pentane T=-78 - 0°C; 3.5 h; 2: ethyl 5-oxo-5-phenylpentanoate in tetrahydrofuran; pentane T=-78°C; 5 h; 3: With silica gel in benzene 10 h; Heating; Further stages.;

1: pentane; tetrahydrofuran / -78 °C 2: SiO2 / benzene / Heating View Scheme

silica gel 1.) pentane, THF, -78 deg C, 2.) benzene, reflux; Yield givenMultistep reaction;

potassium hydroxide; sodium ethanolate 1) EtOH, 8 h, reflux, 2) water, 4 h; Yield given. Multistep reaction;

in methanol Irradiation;