diisobutylaluminium hydride in diethyl ether; hexane T=-78°C;

1.1: bromine; triphenylphosphine / dichloromethane / 2 h / 0 °C 2.1: magnesium 2.2: 3.5 h / -78 °C 3.1: n-butyllithium; N-ethyl-N,N-diisopropylamine / tetrahydrofuran; hexane / 0.5 h / -78 °C 3.2: 2 h / -78 - 20 °C 4.1: diisobutylaluminium hydride / diethyl ether; hexane / -78 °C View Scheme

1.1: magnesium 1.2: 3.5 h / -78 °C 2.1: n-butyllithium; N-ethyl-N,N-diisopropylamine / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.2: 2 h / -78 - 20 °C 3.1: diisobutylaluminium hydride / diethyl ether; hexane / -78 °C View Scheme

1.1: n-butyllithium; N-ethyl-N,N-diisopropylamine / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 2 h / -78 - 20 °C 2.1: diisobutylaluminium hydride / diethyl ether; hexane / -78 °C View Scheme