1.1: oxalyl chloride; DMF / CH2Cl2 / 0 - 20 °C 1.2: Bu4NBH4 / CH2Cl2 / -78 °C 2.1: 84 percent / CBr4; Ph3P / CH2Cl2 / 0 - 20 °C View Scheme

1: 1.) pyridine, 2.) p-toluenesulfonic acid hydrate / 1.) toluene, 20 deg C to 25 deg C, 20 h, 2.) 160 deg C, 24 h 2: 6.5 g / N-bromosuccinimide, dibenzoyl peroxide / CCl4 / 1.5 h / Heating View Scheme

1: lithium perchlorate / toluene / 5 h / Reflux 2: triethylamine; 4-Acetylaminobenzenesulfonyl Azide / acetonitrile / 4 h / 20 °C / Cooling with ice 3: water / dirhodium tetraacetate / tetrahydrofuran / 12 h / 90 °C 4: N-ethyl-N,N-diisopropylamine / tetrahydrofuran / 6.5 h / 20 °C / Cooling with ice 5: hydrogen / palladium(II) oxide hydrate / ethanol; water / 1 h / 20 °C 6: oxalyl dichloride / N,N-dimethyl-formamide / chloroform / 1.5 h / 20 °C / Cooling with ice 7: tetra-N-butylammonium borohydride / chloroform / 1.5 h / -60 °C 8: carbon tetrabromide; triphenylphosphine / chloroform / 18 h / 20 °C View Scheme

1: tetra-N-butylammonium borohydride / chloroform / 1.5 h / -60 °C 2: carbon tetrabromide; triphenylphosphine / chloroform / 18 h / 20 °C View Scheme