1: 50 percent / Et3N, DMAP / CH2Cl2 / 0.5 h / Ambient temperature 2: 38 percent / diethyl ether; tetrahydrofuran / 9 h / Ambient temperature 4: 85 percent / sodium bis(trimethylsilyl)amide / tetrahydrofuran; toluene / 0.5 h / Heating 5: 96 percent / HCl, KF, MeOH / CH2Cl2 / 2 h / Ambient temperature 6: 59 percent / H2O2, NaHCO3, H2O / methanol; tetrahydrofuran / 12 h / Heating View Scheme