diisobutylaluminium hydride in hexane; dichloromethane T=-78 - 20°C;

1: tetrafluoroboric acid diethyl ether complex / dichloromethane / 1 h / 25 - 30 °C / |Inert atmosphere 2: diisobutylaluminium hydride / dichloromethane; hexane / -78 - 20 °C View Scheme