1.1: copper(I) bromide dimethylsulfide complex / tetrahydrofuran / -78 - 0 °C / Inert atmosphere 2.1: 4-(N,N-dimethlyamino)pyridine; triethylamine; methanesulfonyl chloride / dichloromethane / 1.5 h 2.2: 1 h / 70 °C 3.1: sodium periodate; water / ruthenium trichloride / acetonitrile / 5 h / 0 °C 4.1: N,N-dimethyl-formamide; water / 0.25 h 4.2: 0.17 h / 10 °C 4.3: 1 h / 0 °C 5.1: triphenylphosphine / tetrahydrofuran / 2 h / 50 °C 5.2: 10 h View Scheme