1: 90 percent / thiourea / methanol / 2 h / Heating 2: 80 percent / 4A molecular sieves, N-iodosuccinimide, silver triflate / CH2Cl2; toluene / 0.17 h / 0 °C 3: 83 percent / NaOMe, MeOH / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 65 percent / K2CO3 / acetone / Ambient temperature 2: 82 percent / NaOMe, MeOH / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 86 percent / HBr, AcOH / 1,2-dichloro-ethane / 0.5 h / Ambient temperature 2: 65 percent / K2CO3 / acetone / Ambient temperature 3: 82 percent / NaOMe, MeOH / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 65 percent / K2CO3 / acetone / Ambient temperature 2: 92 percent / NaOMe, MeOH / 5 h / Ambient temperature 3: 1.) dibutyltin oxide / 1.) MeOH, reflux, 2 h, 2.) CH2Cl2, 0 deg C, 30 min 4: 91 percent / pyridine / CH2Cl2 / 5 h / 0 °C 5: 90 percent / thiourea / methanol / 2 h / Heating 6: 80 percent / 4A molecular sieves, N-iodosuccinimide, silver triflate / CH2Cl2; toluene / 0.17 h / 0 °C 7: 83 percent / NaOMe, MeOH / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 1.) 3A molecular sieves, 2.) BF3*Et2O / 1.) CH2Cl2, from -25 deg C to -20 deg C, 15 min, 2.) CH2Cl2, 30 min 2: 80.3 percent / NaOMe / methanol View Scheme

1: 1.) 3A molecular sieves, 2.) BF3*Et2O / 1.) CH2Cl2, from -25 deg C to -20 deg C, 15 min, 2.) CH2Cl2, 30 min 2: 80.3 percent / NaOMe / methanol View Scheme

1: 96 percent / AcOH / H2O; diethyl ether / 3 h / Ambient temperature 2: 1.) 3A molecular sieves, 2.) BF3*Et2O / 1.) CH2Cl2, from -25 deg C to -20 deg C, 15 min, 2.) CH2Cl2, 30 min 3: 80.3 percent / NaOMe / methanol View Scheme

pyridine Ambient temperature;