1: sodium tetrahydroborate / methanol / 15 h / 0 - 20 °C 2: triethylamine / dichloromethane / 0 °C 3: lithium bromide / tetrahydrofuran / 2 h / 20 °C / Inert atmosphere 4: triethylamine / N,N-dimethyl-formamide / 9 h / 20 °C 5: ((3aS)-3,3-bis(3,5-dimethylphenyl)-1-(2-(trifluoromethyl)phenyl)hexahydro-1H-pyrrolo[1,2-c][1,3,2]oxazaborol-7-ium-7-yl)tribromoaluminate / dichloromethane / 5.5 h / -75 °C / Inert atmosphere; Irradiation View Scheme

1: sodium tetrahydroborate / methanol / 15 h / 0 - 20 °C 2: triethylamine / dichloromethane / 0 °C 3: lithium bromide / tetrahydrofuran / 2 h / 20 °C / Inert atmosphere View Scheme