sodium hydrogencarbonate in N,N-dimethyl-formamide 96 h; Heating;

1: 95 percent / triethylamine / hexane / ice-water bath, then room temperature, 1 h 2: 1) 30 percent (CF3CO)2O; 2) KOH / 1) CF3COOH, 56 deg C, 56 h; 2) methanol, room temperature View Scheme

1: 95 percent / triethylamine / hexane / ice-water bath, then room temperature, 1 h 2: 1) 30 percent (CF3CO)2O; 2) KOH / 1) CF3COOH, 56 deg C, 56 h; 2) methanol, room temperature View Scheme

1: 100 percent / pyridine / CH2Cl2 / 1.) 0 deg C, 1 h, 2.) 25 deg C, overnight 2: 81 percent / BF3*Et2O / CH2Cl2 / 1.5 h / 0 °C 3: 1.) AlCl3 / 1.) CH2Cl2, 25 deg C, 15 min, 2.) CH2Cl2, 25 deg C, 2 h 4: 79 percent / K2CO3 / methanol; H2O / 2 h / Heating View Scheme

1: 100 percent / pyridine / CH2Cl2 / 1.) 0 deg C, 1 h, 2.) 25 deg C, overnight 2: 81 percent / BF3*Et2O / CH2Cl2 / 1.5 h / 0 °C 3: 1.) AlCl3 / 1.) CH2Cl2, 25 deg C, 15 min, 2.) CH2Cl2, 25 deg C, 2 h View Scheme

1: 100 percent / pyridine / CH2Cl2 / 1.) 0 deg C, 1 h, 2.) 25 deg C, overnight 2: 81 percent / BF3*Et2O / CH2Cl2 / 1.5 h / 0 °C View Scheme