1: 86 percent / H2 / PtO2 / ethyl acetate / 2327.2 Torr 2: KH, MeOH / diethyl ether / 4 h / Heating 3: oxalyl chloride, DMF / acetonitrile / 1.) 0 deg C, 15 min, 2.) -22 deg C, 15 min 4: NH3 / acetonitrile; tetrahydrofuran / 1 h / -76 - 20 °C 5: 99 percent / H2 / 10percent Pd/C / ethyl acetate / 2585.7 Torr 6: 18 percent / 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent) / tetrahydrofuran / 24 h 7: KOH / H2O; tetrahydrofuran / 0.5 h 8: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 9: O2 / Irradiation View Scheme

1: oxalyl chloride, DMF / acetonitrile / 1.) 0 deg C, 15 min, 2.) -22 deg C, 15 min 2: NH3 / acetonitrile; tetrahydrofuran / 1 h / -76 - 20 °C 3: 99 percent / H2 / 10percent Pd/C / ethyl acetate / 2585.7 Torr 4: 18 percent / 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent) / tetrahydrofuran / 24 h 5: KOH / H2O; tetrahydrofuran / 0.5 h 6: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 7: O2 / Irradiation View Scheme

1: KH, MeOH / diethyl ether / 4 h / Heating 2: oxalyl chloride, DMF / acetonitrile / 1.) 0 deg C, 15 min, 2.) -22 deg C, 15 min 3: NH3 / acetonitrile; tetrahydrofuran / 1 h / -76 - 20 °C 4: 99 percent / H2 / 10percent Pd/C / ethyl acetate / 2585.7 Torr 5: 18 percent / 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent) / tetrahydrofuran / 24 h 6: KOH / H2O; tetrahydrofuran / 0.5 h 7: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 8: O2 / Irradiation View Scheme

1: 99 percent / H2 / 10percent Pd/C / ethyl acetate / 2585.7 Torr 2: 18 percent / 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent) / tetrahydrofuran / 24 h 3: KOH / H2O; tetrahydrofuran / 0.5 h 4: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 5: O2 / Irradiation View Scheme

Catalyst M-Chromium oxide; sulfuric acid

chromium(VI) oxide; sulfuric acid in water; acetone T=20°C; 4 h; Cooling with iceDarkness;

chromium(VI) oxide; sulfuric acid in water; acetone T=20°C; 4 h; Cooling with iceDarkness;

1: 18 percent / 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent) / tetrahydrofuran / 24 h 2: KOH / H2O; tetrahydrofuran / 0.5 h 3: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 4: O2 / Irradiation View Scheme

1: KOH / H2O; tetrahydrofuran / 0.5 h 2: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 3: O2 / Irradiation View Scheme

1: 63 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 12 h / Heating 2: O2 / Irradiation View Scheme