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

1: 1.) O3, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 2.) RT 2: 1.) tert-BuOK, 3.) LAH / 1.) THF, RT, 30 min, 2.) THF, 1 h, 3.) ether, RT, 4 h 3: 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 View Scheme

1: 1.) tert-BuOK, 3.) LAH / 1.) THF, RT, 30 min, 2.) THF, 1 h, 3.) ether, RT, 4 h 2: 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 View Scheme

1: LiAlH4 / diethyl ether / 2 h / Ambient temperature 2: (COCl)2 / dimethylsulfoxide; CH2Cl2 / 0.25 h / -78 °C View Scheme

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