1: t-BuOK / toluene / 2 h / 85 °C 2: 3M HCl / 2 h / 80 °C 3: 190 g / toluene / 3 h / 80 - 90 °C 4: Zn, KH2PO4 / tetrahydrofuran; H2O / 2 h / the temperature is kept below 30 deg C 5: NaBH4 / methanol / 1.5 h / Heating View Scheme

1: t-BuOK / toluene / 2 h / 85 °C 2: 3M HCl / 2 h / 80 °C 3: NaBH4 / methanol / 1.5 h / Heating View Scheme