1: 84 percent / potassium t-butoxide / 2-methyl-propan-2-ol; 1,2-dimethoxy-ethane / 50 h / 20 °C 2: 84 percent / n-butyl-lithium, diethylamine / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide 3: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene, -78 deg C, 2.5 h, 2.) room temperature, 30 min 4: 98 percent / m-hydrochloric acid / tetrahydrofuran / 12 h 5: 92 percent / aqueous potassium hydroxide / methanol / 24 h / 20 °C 6: 85 percent / lithium 1,1-dimethylethanethiolate / hexamethylphosphoric acid triamide / 2 h / 70 °C 7: 51 mg / H2 / 5percent Pd-C / ethyl acetate 8: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 91 percent / polyphosphoric acid / 2 h / 70 °C 2: 84 percent / potassium t-butoxide / 2-methyl-propan-2-ol; 1,2-dimethoxy-ethane / 50 h / 20 °C 3: 84 percent / n-butyl-lithium, diethylamine / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide 4: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene, -78 deg C, 2.5 h, 2.) room temperature, 30 min 5: 98 percent / m-hydrochloric acid / tetrahydrofuran / 12 h 6: 92 percent / aqueous potassium hydroxide / methanol / 24 h / 20 °C 7: 85 percent / lithium 1,1-dimethylethanethiolate / hexamethylphosphoric acid triamide / 2 h / 70 °C 8: 51 mg / H2 / 5percent Pd-C / ethyl acetate 9: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 88 percent / anhydrous potassium carbonate, 18-crown-6 / acetone / 24 h / 20 °C 2: 51 percent / potassium t-butoxide / 1,2-dimethoxy-ethane; 2-methyl-propan-2-ol 3: 87 percent / n-butyl-lithium, diethylamine / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 30 min, 2.) room temperature, 1 h 4: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene 5: 96 percent / toluene-p-sulphonic acid / acetone; H2O / 20 h / 20 °C 6: 87 percent / aqueous potassium hydroxide / methanol 7: 1.) boron trichloride / 1.) dichloromethane, -78 deg C, 1 h, 2.) methanol, - 78 deg C -> room temperature 8: 51 mg / H2 / 5percent Pd-C / ethyl acetate 9: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 84 percent / n-butyl-lithium, diethylamine / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide 2: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene, -78 deg C, 2.5 h, 2.) room temperature, 30 min 3: 98 percent / m-hydrochloric acid / tetrahydrofuran / 12 h 4: 92 percent / aqueous potassium hydroxide / methanol / 24 h / 20 °C 5: 85 percent / lithium 1,1-dimethylethanethiolate / hexamethylphosphoric acid triamide / 2 h / 70 °C 6: 51 mg / H2 / 5percent Pd-C / ethyl acetate 7: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 51 percent / potassium t-butoxide / 1,2-dimethoxy-ethane; 2-methyl-propan-2-ol 2: 87 percent / n-butyl-lithium, diethylamine / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 30 min, 2.) room temperature, 1 h 3: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene 4: 96 percent / toluene-p-sulphonic acid / acetone; H2O / 20 h / 20 °C 5: 87 percent / aqueous potassium hydroxide / methanol 6: 1.) boron trichloride / 1.) dichloromethane, -78 deg C, 1 h, 2.) methanol, - 78 deg C -> room temperature 7: 51 mg / H2 / 5percent Pd-C / ethyl acetate 8: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 92 percent / aqueous potassium hydroxide / methanol / 24 h / 20 °C 2: 85 percent / lithium 1,1-dimethylethanethiolate / hexamethylphosphoric acid triamide / 2 h / 70 °C 3: 51 mg / H2 / 5percent Pd-C / ethyl acetate 4: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 87 percent / n-butyl-lithium, diethylamine / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 30 min, 2.) room temperature, 1 h 2: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene 3: 96 percent / toluene-p-sulphonic acid / acetone; H2O / 20 h / 20 °C 4: 87 percent / aqueous potassium hydroxide / methanol 5: 1.) boron trichloride / 1.) dichloromethane, -78 deg C, 1 h, 2.) methanol, - 78 deg C -> room temperature 6: 51 mg / H2 / 5percent Pd-C / ethyl acetate 7: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 98 percent / m-hydrochloric acid / tetrahydrofuran / 12 h 2: 92 percent / aqueous potassium hydroxide / methanol / 24 h / 20 °C 3: 85 percent / lithium 1,1-dimethylethanethiolate / hexamethylphosphoric acid triamide / 2 h / 70 °C 4: 51 mg / H2 / 5percent Pd-C / ethyl acetate 5: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 1.) di-isobutylaluminium hydride, 2.) aqueous acetic acid / 1.) toluene, -78 deg C, 2.5 h, 2.) room temperature, 30 min 2: 98 percent / m-hydrochloric acid / tetrahydrofuran / 12 h 3: 92 percent / aqueous potassium hydroxide / methanol / 24 h / 20 °C 4: 85 percent / lithium 1,1-dimethylethanethiolate / hexamethylphosphoric acid triamide / 2 h / 70 °C 5: 51 mg / H2 / 5percent Pd-C / ethyl acetate 6: 7 percent / sodium borohydride / methanol / 3 h View Scheme

1: 87 percent / aqueous potassium hydroxide / methanol 2: 1.) boron trichloride / 1.) dichloromethane, -78 deg C, 1 h, 2.) methanol, - 78 deg C -> room temperature 3: 51 mg / H2 / 5percent Pd-C / ethyl acetate 4: 7 percent / sodium borohydride / methanol / 3 h View Scheme