1: in tetrahydrofuran T=20°C; 0.5 h; Inert atmosphere; 2: With phosphonic acid diethyl ester in tetrahydrofuran Inert atmosphere;

in diethyl ether T=20°C; 23 h; Inert atmosphereCooling with ice;

1: phosphorous tribromide / CH2Cl2 / 1 h / Ambient temperature 2: 80 percent / diethyl ether / 30 h / Ambient temperature View Scheme

1: lithium aluminum hydride / diethyl ether / 16 h / Ambient temperature 2: phosphorous tribromide / CH2Cl2 / 1 h / Ambient temperature 3: 80 percent / diethyl ether / 30 h / Ambient temperature View Scheme

phosphorus tribromide 1.) THF, 30 min, 2.) THF, Et2O, 12 h; Yield given. Multistep reaction;

1: hexane; toluene / 4.5 h / 40 °C 2: dihydrogen peroxide; sodium hydroxide / water; toluene 3: carbon tetrabromide; triphenylphosphine / acetonitrile / 1 h / 20 °C / Cooling with ice 4: boron tribromide / dichloromethane; 1,2-dichloro-ethane / 1.5 h / Reflux 5: boron trifluoride diethyl etherate; magnesium sulfate / dichloromethane / 1 h / -40 °C / Inert atmosphere 6: 2,6-dimethylpyridine / dichloromethane / 20 °C 7: dilithium tetrachlorocuprate / tetrahydrofuran / 3 h / 20 °C 8: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.5 h / 20 °C View Scheme