1.1: Et3N / ethyl acetate / 20 °C 2.1: 90 percent / KOH / H2O; ethanol / 3 h / 40 °C 3.1: NaH; 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone / tetrahydrofuran / 0.5 h / 20 °C 3.2: BuLi / tetrahydrofuran; hexane / -78 - 20 °C 3.3: 12 percent / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

pyridinium hydrobromide perbromide in acetic acid Ambient temperature;

water; hydrogen cation; zinc in benzene T=40°C;

1: K2CO3 / tetrahydrofuran / Heating 2: pyridinium tribromide; acetic acid / 20 °C View Scheme

1: 91 percent / triethylamine / CH2Cl2 / 6 h / 20 °C 2: 89 percent / potassium hydroxide / H2O; ethanol / 3 h / 20 °C 3: 83 percent / ethyldiisopropylamine / CH2Cl2 / 0 °C View Scheme

triethylamine in dichloromethane T=20°C; 6 h;