1: With zirconocene dichloride; diisobutylaluminium hydride in tetrahydrofuran; hexane T=0 - 20°C; 2 h; 2: With N-iodo-succinimide in tetrahydrofuran; hexane T=-78°C; 0.5 h;

1.1: 1H-imidazole / dichloromethane / 0.17 h / 0 °C 1.2: 17 h / 0 - 20 °C 2.1: zirconocene dichloride; diisobutylaluminium hydride / tetrahydrofuran; hexane / 2 h / 0 - 20 °C 2.2: 0.5 h / -78 °C View Scheme

1.1: 1H-imidazole / dichloromethane / 0.17 h / 0 °C 1.2: 17 h / 0 - 20 °C 2.1: zirconocene dichloride; diisobutylaluminium hydride / tetrahydrofuran; hexane / 2 h / 0 - 20 °C 2.2: 0.5 h / -78 °C View Scheme