1: oxalyl dichloride / dichloromethane / 1 h / 20 °C 2: sodium azide / water; acetone / 1 h / 0 °C 3: benzene / 1 h / Reflux 4: dichloromethane / 2 h / 20 °C 5: sodium hydride / tetrahydrofuran / 1 h / 0 °C 6: N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile / benzene / 5 h / 70 °C 7: potassium tert-butylate / tert-butyl alcohol / 0.25 h / 70 - 85 °C View Scheme

1: NEt3 / tetrahydrofuran / 0.5 h / -15 °C 2: NaBH4 / H2O; tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: NEt3 / tetrahydrofuran / 0.5 h / -15 °C 2: NaBH4 / H2O; tetrahydrofuran / 2 h / Ambient temperature 3: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -40 deg C, 25 min, 2.) CH2Cl2, -40 deg C, 5 min View Scheme