1: 80 percent / PBr3 / 1 h / 85 °C 2: acetonitrile / 24 h / Heating 3: 60 percent / 1. NaHMDS / tetrahydrofuran / 1. -78 deg C, 1h 2. 25 deg C, 20h View Scheme

1: 64 percent / pyridine 2: 92 percent / NaI / acetone 3: 86 percent / 1.) n-BuLi, 2.) HMPT / 1.) THF-hexane, 0 deg C, 1 h; -> RT, 1 h, 2.) 0 deg C -> RT; then RT, overnight 4: 86 percent / p-TsOH 5: 99.3 percent / sodium bis(methoxyethoxy)aluminum hydride / diethyl ether; toluene / 48 h / Ambient temperature View Scheme

oxalyl dichloride in dichloromethane; dimethyl sulfoxide T=-78°C; 0.25 h; Yield given;

1: 1.) (COCl)2, DMSO, 3.) triethylamine / 1.) CH2Cl2, -70 deg C, 5 min, 2.) 20 min, -70 deg C, 3.) 5 min at -70 deg C, -70 deg C to RT 2: 1.) n-BuLi / 1.) THF, tetramethylethylenediamine, hexane, 0 to 20 deg C; 2.) THF, RT, 1 h 3: Lithium / tetrahydrofuran; liquid ammonia / -30 °C / large excess of lithium 4: 93 percent / 48 percent HBr / ethanol / 0.25 h / 65 °C 5: 81 percent / O2 / salcomine / dimethylformamide / 3 h / Ambient temperature 6: 77 percent / 70 percent HClO4 / CH2Cl2 / 1 h / Ambient temperature View Scheme

carbon tetrabromide; triphenylphosphine in dichloromethane 1.) from 0 deg C to 20 deg C, 1 h, 2) 20 deg C, 14 h;

1: PBr3 2: 98 percent / acetonitrile / 24 h / Heating 3: NaOEt / tetrahydrofuran / 1 h / 25 °C 4: n-BuLi / toluene / 2 h / 25 °C View Scheme