1: With sodium tetrahydroborate in tetrahydrofuran T=10 - 15°C; 0.5 h; Inert atmosphereIndustry scale; 2: With AlCl3, aluminium chloride in tetrahydrofuran T=-5 - 70°C; 20 h; Inert atmosphere; 3: With water T=0 - 40°C; Inert atmosphere;

potassium hydroxide; BF3.Et2O; Et3SiH in water; acetonitrile

1.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 20 h / 20 °C 1.2: 3 h / 0 - 24 °C 2.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane / 1 h / 0 - 24 °C View Scheme

1.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 20 h / 20 °C 1.2: 3 h / 0 - 24 °C 2.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane / 1 h / 0 - 24 °C View Scheme

1: AlCl3, aluminium chloride / dichloromethane / 1 h / -5 - 0 °C 2: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / -20 - 20 °C View Scheme

1: With boron trichloride in dichloromethane T=0°C; 0.5 h; Inert atmosphere; 2: With boron tribromide in dichloromethane T=0°C;