1.1: TMEDA; n-BuLi / tetrahydrofuran; hexane / 2 h / 0 °C 1.2: 48 percent / ethanol; hexane / 2.5 h / -78 - 20 °C 2.1: 99 percent / HCl / 1,2-dimethoxy-ethane / 5 h / Heating 3.1: 90 percent / p-TsOH*H2O / methanol / 6 h / Heating 4.1: 91 percent / NaH; O-(diphenylphosphinyl)hydroxylamine / tetrahydrofuran / 0.75 h / 0 - 20 °C 5.1: H2SO4 / H2O / 4 h / 20 - 85 °C View Scheme