triethyl phosphite in N,N-dimethyl-formamide T=100°C; 2 h;

1.1: LDA / tetrahydrofuran / -30 °C 1.2: tetrahydrofuran / -30 - 0 °C 2.1: Cu(OAc)2; NH4OAc; HOAc / 4 h / 115 °C View Scheme

1.1: LDA / tetrahydrofuran / -30 °C 1.2: tetrahydrofuran / -30 - 0 °C 2.1: Cu(OAc)2; NH4OAc; HOAc / 4 h / 115 °C View Scheme

1: 1.) LDA / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, hexane, from -78 deg C to RT 2: 74 percent / 3 N aq. HCl, NaNO2 / 0.5 h / Ambient temperature 3: NH4OAc, CH3CO2H / 18 h / Heating 4: P(OEt)3 / dimethylformamide / 2 h / 100 °C View Scheme

1: 74 percent / 3 N aq. HCl, NaNO2 / 0.5 h / Ambient temperature 2: NH4OAc, CH3CO2H / 18 h / Heating 3: P(OEt)3 / dimethylformamide / 2 h / 100 °C View Scheme

1: 100 percent / Et3N / CH2Cl2 / 0.5 h 2: 1.) LDA / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, hexane, from -78 deg C to RT 3: 74 percent / 3 N aq. HCl, NaNO2 / 0.5 h / Ambient temperature 4: NH4OAc, CH3CO2H / 18 h / Heating 5: P(OEt)3 / dimethylformamide / 2 h / 100 °C View Scheme

copper diacetate; ammonium acetate; acetic acid T=115°C; 4 h;