1.1: sodium tris(acetoxy)borohydride; acetic acid / 1,2-dichloro-ethane / 6 h / 20 °C 2.1: potassium carbonate / ethanol; water; toluene / 1 h / 20 °C 2.2: 3 h / Heating / reflux 3.1: lithium hexamethyldisilazane / tetrahydrofuran; hexane / 2 h / -78 °C 3.2: 2 h / 20 °C 4.1: thionyl chloride / N,N-dimethyl-formamide / tetrahydrofuran / 1 h / 20 °C 5.1: triethylamine / tetrahydrofuran; DMF (N,N-dimethyl-formamide) / 16 h / 0 - 20 °C View Scheme

4-(N,N-dimethlyamino)pyridine in tetrahydrofuran 1.5 h; Heating;

1: DMAP / tetrahydrofuran / 1.5 h / Heating 2: 3.89 g / sodium methoxide / 2.5 h / Heating 3: NaBH4 / tetrahydrofuran; methanol / 1 h / -15 °C 4: Et3N / tetrahydrofuran / 14 h / 20 °C 5: 2.53 g / 1,8-diazabicyclo[5,4,0]undec-7-ene / tetrahydrofuran / 0.17 h / Heating 6: 100 percent / aq. HCl / ethyl acetate / 0.5 h / 80 °C View Scheme

1: With hydrogenchloride; water; acetic acid 1 h; Heating / reflux; 2: With potassium hydroxide in water pH=8;

1.1: NaH / dimethylformamide / 1 h / 20 °C 1.2: NaI / dimethylformamide / 14 h / 80 °C 2.1: 25.1 g / NaH / dimethylformamide / 15 h / 80 °C 3.1: 21 percent / H2SO4; AcOH / 2.5 h / 90 °C View Scheme

1.1: 88 percent / pyridine / 1 h / 55 °C 2.1: NaH / dimethylformamide / 1 h / 20 °C 2.2: NaI / dimethylformamide / 14 h / 80 °C 3.1: 25.1 g / NaH / dimethylformamide / 15 h / 80 °C 4.1: 21 percent / H2SO4; AcOH / 2.5 h / 90 °C View Scheme

pyridine in dichloromethane T=0°C; 1.5 h;