1: 3.6 g / imidazole / dimethylformamide / 48 h / 38 °C 2: 67 percent / LiAlH4 / diethyl ether / 1.5 h / Heating 3: 95 percent / chromic oxide, pyridine / CH2Cl2; dimethylformamide / 1 h / Ambient temperature 4: 89 percent / sodium chlorite, 2-methyl-2-butene, sat. aq. potassium dihydrogen phosphate, t-BuOH / 5 h / Ambient temperature 5: 56 percent / tetrabutylammonium fluoride / tetrahydrofuran / 0.25 h / 0 °C View Scheme

lithium aluminium tetrahydride

1: 3.6 g / imidazole / dimethylformamide / 48 h / 38 °C 2: 67 percent / LiAlH4 / diethyl ether / 1.5 h / Heating 3: 95 percent / chromic oxide, pyridine / CH2Cl2; dimethylformamide / 1 h / Ambient temperature View Scheme

boron trifluoride diethyl etherate in dichloromethane T=-20°C;

2: sodium chromate / acetic acid; acetic anhydride / 72 h / 35 °C 3: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran 4: boron trifluoride etherate / CH2Cl2 / -20 °C View Scheme

2: sodium chromate / acetic acid; acetic anhydride / 72 h / 35 °C 3: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran 4: boron trifluoride etherate / CH2Cl2 / -20 °C View Scheme

1: sodium chromate / acetic acid; acetic anhydride / 72 h / 35 °C 2: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran 3: boron trifluoride etherate / CH2Cl2 / -20 °C View Scheme

1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran 2: boron trifluoride etherate / CH2Cl2 / -20 °C View Scheme