1: 24.3 g / p-toluenesulfonic acid / toluene / 6 h / Heating 2: 2.5 g / BuLi / diethyl ether; hexane / 4 h / -50 °C 3: 1.) NaH, 2.) conc. HCl / 1.) DME, 2 h, 2.) ethanol, H2O, steam bath, 10 min 4: 1.) BuLi, 2.) NaOH / 1.) hexane, toluene, 75 deg C, 2 h, 2.) ethanol, steam bath, 10 min View Scheme

n-butyllithium in diethyl ether; hexane T=-50°C; 3 h;

thionyl chloride; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran; methanol; dichloromethane; water

thionyl chloride in tetrahydrofuran; methanol; dichloromethane; water

sodium carbonate; toluene-4-sulfonic acid in ethylene glycol; benzene

sodium carbonate in ethylene glycol; benzene

toluene-4-sulfonic acid in toluene 6 h; Heating;

tributyl-amine; triphenylphosphine in water; ethyl acetate

1: 24.3 g / p-toluenesulfonic acid / toluene / 6 h / Heating 2: 2.5 g / BuLi / diethyl ether; hexane / 4 h / -50 °C 3: 1.) NaH, 2.) conc. HCl / 1.) DME, 2 h, 2.) ethanol, H2O, steam bath, 10 min View Scheme