1.1: NaBH4 / ethanol / 4 h / 50 °C 1.2: 90 percent / aq. H2SO4 / ethanol / 1 h / 80 °C 2.1: 82 percent / potassium n-butylthioxanthogenate / N,N-dimethyl-acetamide / 6 h / 125 °C 3.1: t-BuOK / toluene / 0.75 h / 25 °C 3.2: 81 percent / toluene / 7 h / 135 °C 4.1: 95 percent / H2 / Pd(OH)2/C / ethyl acetate / 4 h / 3040 Torr 5.1: 80 percent / methanesulfonic acid; aq. AcOH / xylene / 10 h / Heating View Scheme