1: in methanol T=20°C; 0.5 h; Inert atmosphere; 2: With sodium tetrahydroborate in methanol T=0 - 20°C; 0.666667 h; Inert atmosphere;

1: 2 h / Inert atmosphere; Reflux 2: bromine; sodium hydrogencarbonate / dichloromethane; water / 4 h / 0 - 20 °C / Inert atmosphere 3: borane-THF / tetrahydrofuran / 1.5 h / 0 - 20 °C / Inert atmosphere View Scheme