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 View Scheme

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