1.1: lithium borohydride / tetrahydrofuran / 20 h / 0 - 20 °C 1.2: pH 7 2.1: phosphorus tribromide / toluene / 3 h / 20 - 35 °C View Scheme

1: With lithium borohydride in tetrahydrofuran 20 h; Cooling with ice; 2: With hydrogenchloride in tetrahydrofuran; water pH=7;