1: 90 percent / NaBH4 / methanol / 24 h / Ambient temperature 2: 83 percent / TsOH / toluene / 10 h / Heating 3: 95 percent / 5N aq. HCl / ethanol / 6 h / Heating 4: 1.) aq. H2SO, NaNO2, 2.) aq. KI / 1.) 0 deg C, 1 h, 2.) RT, overnight View Scheme