1.1: 94 percent / LiBH4 / tetrahydrofuran / 96 h / 0 °C 2.1: mercuric trifluoroacetate / 1,2-dimethoxy-ethane / 2 h / 20 °C 2.2: NaBH4; aq. NaOH / 1,2-dimethoxy-ethane / 0.08 h / 20 °C 3.1: montmorillonite K-10 / CH2Cl2 / 22 h / 20 °C View Scheme

1: 84 percent / aq. KOH / ethanol / 5 h / 20 °C 2: 60 percent / trifluoroacetic acid / CHCl3 / 48 h / 20 °C 3: 84 percent / thionyl chloride; pyridine / 0.5 h / 20 °C 4: montmorillonite K-10 / CH2Cl2 / 144 h / Heating View Scheme