1: 36 percent / NaBH4 / methanol / 1 h / Heating 2: 47 percent / MnO2 / CH2Cl2 / Ambient temperature 3: 51 percent / ethanol / Ambient temperature 4: 2) HCOOH / 1) 80 deg C, DMSO, overnight, 2) H2O, MeOH, reflux, 12 h View Scheme