in acetonitrile

1.1: sodium tetrahydroborate / ethanol / 17 h / 10 - 19 °C / |Inert atmosphere; |Large scale 2.1: boron trifluoride diethyl etherate / tetrahydrofuran / 0.43 h / 5 - 10 °C / |Inert atmosphere; |Large scale 2.2: 17.3 h / 8 - 20 °C / |Inert atmosphere; |Large scale 2.3: |Large scale 3.1: sulfur trioxide pyridine complex; triethylamine / water / 1 h / 22 °C / |Inert atmosphere; |Large scale View Scheme

sodium tetrahydroborate in ethanol T=10 - 19°C; 17 h; Inert atmosphereLarge scale;

1: copper-powder / 270 °C 2: KMnO4; H2O View Scheme

copper T=270°C;