1: With lithium hydroxide; water in tetrahydrofuran T=0 - 17°C; 31.5 h; 2: With hydrogenchloride; potassium chloride in tetrahydrofuran; water T=0°C; pH=5.3 - 6; 1 h; 3: With sulfuric acid in water T=20°C; 2.5 h;

ammonium cerium (IV) nitrate; water in acetonitrile T=-5°C; 1.58333 h; Cooling with acetone-dry ice;

in chlorobenzene T=131°C; 4 h;

ammonium cerium(IV) nitrate in water; acetonitrile T=-3°C; 0.5 h;

1: 94 percent / Fremy's salt, KH2PO4 / acetonitrile; H2O / 0.5 h / 20 °C 2: 47 percent / Et3N / tetrahydrofuran / 1 h / 20 °C 3: 1.) N-chlorosuccinimide, triethylamine; 2.) DDQ, Et3N / 1.) methylene chloride, 20 deg C, 30 min; 2.) methylene chloride, 20 deg C, 90 min 4: 85 percent / trifluoroacetic acid / 1 h / 20 °C 5: 82 percent / chlorobenzene / 4 h / 131 °C View Scheme

1: 47 percent / Et3N / tetrahydrofuran / 1 h / 20 °C 2: 1.) N-chlorosuccinimide, triethylamine; 2.) DDQ, Et3N / 1.) methylene chloride, 20 deg C, 30 min; 2.) methylene chloride, 20 deg C, 90 min 3: 85 percent / trifluoroacetic acid / 1 h / 20 °C 4: 82 percent / chlorobenzene / 4 h / 131 °C View Scheme

1: 47 percent / Et3N / tetrahydrofuran / 1 h / 20 °C 2: 1.) N-chlorosuccinimide, triethylamine; 2.) DDQ, Et3N / 1.) methylene chloride, 20 deg C, 30 min; 2.) methylene chloride, 20 deg C, 90 min 3: 85 percent / trifluoroacetic acid / 1 h / 20 °C 4: 82 percent / chlorobenzene / 4 h / 131 °C View Scheme

1: 98 percent / H2 / PtO2 / methanol / 3 h 2: 89 percent / concd. HCl, aq. NaNO2 / 0.33 h / 0 °C 3: HOAc, 50percent aq. H3PO2 / 1 h / Ambient temperature View Scheme

1: Et3N, MnO2 / CH2Cl2 2: 85 percent / trifluoroacetic acid / 1 h / 20 °C 3: 82 percent / chlorobenzene / 4 h / 131 °C View Scheme

hypophosphorous ether; potassium hexacyanoferrate(III) 1.) acetic acid, 25 deg C, 20 min; Yield given. Multistep reaction;