phosphoric acid triethylester in diethyl ether

potassium carbonate in N,N-dimethyl-formamide T=120°C;

tri-n-butyl-tin hydride in ethanol T=50 - 60°C; 1 h;

1: 75 percent / pyridine / tetrahydrofuran / 1.5 h / Heating 3: 91 percent / satd. NaHCO3 / ethanol / 2 h / 50 - 60 °C 4: 93 percent / triphenylphosphite methiodide / dimethylformamide / 1.5 h / Ambient temperature 5: 73 percent / tri-n-butyltin hydride / ethanol / 1 h / 50 - 60 °C View Scheme

1: 93 percent / triphenylphosphite methiodide / dimethylformamide / 1.5 h / Ambient temperature 2: 73 percent / tri-n-butyltin hydride / ethanol / 1 h / 50 - 60 °C View Scheme

2: 91 percent / satd. NaHCO3 / ethanol / 2 h / 50 - 60 °C 3: 93 percent / triphenylphosphite methiodide / dimethylformamide / 1.5 h / Ambient temperature 4: 73 percent / tri-n-butyltin hydride / ethanol / 1 h / 50 - 60 °C View Scheme

1: 91 percent / satd. NaHCO3 / ethanol / 2 h / 50 - 60 °C 2: 93 percent / triphenylphosphite methiodide / dimethylformamide / 1.5 h / Ambient temperature 3: 73 percent / tri-n-butyltin hydride / ethanol / 1 h / 50 - 60 °C View Scheme

hydrogenchloride; acetic acid