1: 98 percent / p-TsOH / CH2Cl2 / 1 h / -15 - -10 °C 2: 81 percent / m-chloroperbenzoic acid / CH2Cl2 / 8 h / 0 °C 3: 90 percent / <(i-PrO)3P>4Pd / tetrahydrofuran; dimethylsulfoxide; hexane / 1) 0 deg C, 3 h, 2) rt, 16 h 4: 64 percent / methanol; dimethylsulfoxide / 16 h / 90 °C 5: 90 percent / dimethylaminopyridine, Et2NSF3 / CH2Cl2 / 1) -78 deg C to rt, 2 h, 2) rt, 22 h 6: 30percent aq. NH4OH / methanol / 12 h 7: 10 percent aq. HCl / 3 h View Scheme

1: 81 percent / m-chloroperbenzoic acid / CH2Cl2 / 8 h / 0 °C 2: 90 percent / <(i-PrO)3P>4Pd / tetrahydrofuran; dimethylsulfoxide; hexane / 1) 0 deg C, 3 h, 2) rt, 16 h 3: 64 percent / methanol; dimethylsulfoxide / 16 h / 90 °C 4: 90 percent / dimethylaminopyridine, Et2NSF3 / CH2Cl2 / 1) -78 deg C to rt, 2 h, 2) rt, 22 h 5: 30percent aq. NH4OH / methanol / 12 h 6: 10 percent aq. HCl / 3 h View Scheme

1: 90 percent / <(i-PrO)3P>4Pd / tetrahydrofuran; dimethylsulfoxide; hexane / 1) 0 deg C, 3 h, 2) rt, 16 h 2: 64 percent / methanol; dimethylsulfoxide / 16 h / 90 °C 3: 90 percent / dimethylaminopyridine, Et2NSF3 / CH2Cl2 / 1) -78 deg C to rt, 2 h, 2) rt, 22 h 4: 30percent aq. NH4OH / methanol / 12 h 5: 10 percent aq. HCl / 3 h View Scheme

1: 30percent aq. NH4OH / methanol / 12 h 2: 10 percent aq. HCl / 3 h View Scheme