bromine; acetic acid

1: N2H4 2: bromine; aqueous acetic acid View Scheme

1: R-(+)-proline / acetonitrile / 12 h / 0 °C 2: sodium chlorite; aminosulfonic acid / dichloromethane; water / 0 °C / |Large scale 3: sodium hydride / N,N-dimethyl-formamide / 12 h / 0 - 25 °C View Scheme

1.1: (R)-proline / acetonitrile / 15 h / 0 °C 1.2: 100 percent / NaBH4 / acetonitrile; ethanol / 0.67 h / 0 °C 2.1: 82 percent / imidazole / dimethylformamide / 3.5 h / 23 °C 3.1: 90 percent / NaH / dimethylformamide / 0.67 h / 0 °C 4.1: 97 percent / TBAF / tetrahydrofuran / 0.67 h / 0 °C 5.1: 91 percent / TEMPO; NaClO2; aq. NaClO / aq. phosphate buffer; acetonitrile / 4 h / 23 °C / pH 6.8 View Scheme

1: R-(+)-proline / acetonitrile / 12 h / 0 °C 2: sodium chlorite; aminosulfonic acid / dichloromethane; water / 0 °C / |Large scale 3: sodium hydride / N,N-dimethyl-formamide / 12 h / 0 - 25 °C View Scheme

in dichloromethane T=20°C; 1.5 h;