chromium(VI) oxide; acetic acid T=70 - 100°C;

1: tri-ruthenium(0)dodecacarbonyl; 1,3-bis-(diphenylphosphino)propane / toluene / 24 h / 130 °C / |Sealed tube; |Inert atmosphere 2: tetrabutylammonium dioxovanadium(V)-dipicolinate; sodium sulfite / benzene / 96 h / 180 °C / |Sealed tube 3: carbon / benzene / 12 h / 80 °C / 760.05 Torr / |Sealed tube View Scheme

1.1: hydroquinone / benzene / 15 h / 180 °C / |Sealed tube; |Inert atmosphere 2.1: sodium hydroxide / water / 0.5 h / 40 °C 2.2: pH 4 3.1: tri-ruthenium(0)dodecacarbonyl; 1,3-bis-(diphenylphosphino)propane / toluene / 24 h / 130 °C / |Sealed tube; |Inert atmosphere 4.1: tetrabutylammonium dioxovanadium(V)-dipicolinate; sodium sulfite / benzene / 96 h / 180 °C / |Sealed tube 5.1: carbon / benzene / 12 h / 80 °C / 760.05 Torr / |Sealed tube View Scheme

1.1: sodium hydroxide / water / 0.5 h / 40 °C 1.2: pH 4 2.1: tri-ruthenium(0)dodecacarbonyl; 1,3-bis-(diphenylphosphino)propane / toluene / 24 h / 130 °C / |Sealed tube; |Inert atmosphere 3.1: tetrabutylammonium dioxovanadium(V)-dipicolinate; sodium sulfite / benzene / 96 h / 180 °C / |Sealed tube 4.1: carbon / benzene / 12 h / 80 °C / 760.05 Torr / |Sealed tube View Scheme