aq. acid 1 h; Ambient temperature;

1: triethylamine / CHCl3 / 1.) 3h, reflux, 2.) room temp. 2: HCl / dioxane; H2O / 1 h / 100 °C 3: sulphur / 3 h / Heating 4: 90 percent / NaOH / H2O; dimethylsulfoxide / 8 h / 120 °C View Scheme

1: 67.4 percent / triethylamine / CHCl3 / 1.) 3h, reflux, 2.) room temp. 2: 90 percent / HCl / dioxane; H2O / 1 h / 100 °C 3: 98.5 percent / diisobutylaluminum hydride / toluene / 1.) 15 min. -10 deg C. 2.) 2 h, room temp. 4: 89 percent / 63percent HBr / H2O / 8 h / 80 - 90 °C View Scheme