1: 96 percent / TFA / H2O; CHCl3 / 10 h / 70 °C 2: 84 percent / pyridine / 4 h / Ambient temperature 3: 1.) PPh3, DEAD, 2.) MeI / 1.) benzene, rt, 24 h, 2.) toluene, rt, 30 min, reflux, 24 h 4: 60 percent / H2 / Pd/C / ethanol / 12 h / Ambient temperature 5: 77 percent / p-TsOH / methanol / 5 h / Ambient temperature View Scheme

trifluoroacetic acid in chloroform; water T=70°C; 10 h;

1: 96 percent / TFA / H2O; CHCl3 / 10 h / 70 °C 2: 84 percent / pyridine / 4 h / Ambient temperature 3: 1.) PPh3, DEAD, 2.) MeI / 1.) benzene, rt, 24 h, 2.) toluene, rt, 30 min, reflux, 24 h 4: 60 percent / H2 / Pd/C / ethanol / 12 h / Ambient temperature View Scheme

1: 96 percent / TFA / H2O; CHCl3 / 10 h / 70 °C 2: 84 percent / pyridine / 4 h / Ambient temperature 3: 1.) PPh3, DEAD, 2.) MeI / 1.) benzene, rt, 24 h, 2.) toluene, rt, 30 min, reflux, 24 h View Scheme