1.1: water; sodium tetrahydroborate; methanol / ethyl acetate / 10 - 20 °C 2.1: sulfuric acid / 0 - 30 °C 2.2: 10 °C / pH 7 - 8 3.1: sodium tetrahydroborate / tetrahydrofuran / -5 - 5 °C 3.2: 5 - 20 °C 4.1: sodium hydroxide / 20 °C / pH 7.5 - 8 5.1: isopropyl alcohol; acetonitrile / 1 h / 70 °C / Reflux 6.1: sodium hydrogencarbonate / ethyl acetate / 20 °C 6.2: 0.67 h View Scheme