1: 92 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2: 99 percent / NH2OH*HCl; Na2CO3 / H2O / 1 h / 20 °C 3: 84 percent / LAH / diethyl ether; diisopropyl ether / 24 h / 55 °C 4: 96 percent / Et3N / CH2Cl2 / 1 h 5: 5 percent / TiCl4 / CHCl3 / 3.3 h / 20 °C View Scheme

1: 92 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2: 99 percent / NH2OH*HCl; Na2CO3 / H2O / 1 h / 20 °C 3: 84 percent / LAH / diethyl ether; diisopropyl ether / 24 h / 55 °C 4: 96 percent / Et3N / CH2Cl2 / 1 h 5: 93 percent / TiCl4 / CHCl3 / 3.3 h / 20 °C 6: 98 percent / TBAF; H2O2; KHCO3 / tetrahydrofuran; H2O; methanol / 6 h / 40 °C View Scheme