carbon dioxide

1.1: potassium dihydrogenphosphate; Fremy’s salt / methanol; water / 1 h / 0 °C 2.1: platinum(IV) oxide; hydrogen / tetrahydrofuran / 2 h / 24 °C 3.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 1 h / 0 °C 3.2: 20 h / 0 - 24 °C 4.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / 0 °C 4.2: 1 h / 0 °C 5.1: tetrakis(triphenylphosphine) palladium(0); potassium carbonate / 1,4-dioxane; water / 2 h / 24 °C / Reflux 6.1: toluene-4-sulfonic acid; 2,3-dicyano-5,6-dichloro-p-benzoquinone / benzene / 0.4 h / 24 - 50 °C 7.1: platinum(IV) oxide; hydrogen / tetrahydrofuran / 1 h / 24 °C 8.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C / Inert atmosphere 8.2: 17 h / -78 - 0 °C / Inert atmosphere 9.1: AlCl3, aluminium chloride; ethane-1,2-dithiol / nitromethane / 0.5 h / -20 °C View Scheme