1.1: borane-THF / tetrahydrofuran / 0.5 h / -78 - 0 °C / Inert atmosphere 2.1: lithium hexamethyldisilazane / tetrahydrofuran; N,N-dimethyl-formamide / 0.02 h / -78 °C / Inert atmosphere 2.2: 0.33 h / -78 - 20 °C / Inert atmosphere 3.1: trifluoroacetic acid / dichloromethane / 1.5 h / 20 °C / Inert atmosphere 4.1: manganese(IV) oxide / dichloromethane / 1 h / 20 °C / Inert atmosphere View Scheme

1.1: borane-THF / tetrahydrofuran / 0.5 h / -78 - 0 °C / Inert atmosphere 2.1: lithium hexamethyldisilazane / tetrahydrofuran; N,N-dimethyl-formamide / 0.02 h / -78 °C / Inert atmosphere 2.2: 0.33 h / -78 - 20 °C / Inert atmosphere 3.1: trifluoroacetic acid / dichloromethane / 1.5 h / 20 °C / Inert atmosphere 4.1: manganese(IV) oxide / dichloromethane / 1 h / 20 °C / Inert atmosphere View Scheme