carbonic acid dimethyl ester in dichloromethane T=20°C; 2 h;

carbonic acid dimethyl ester in dichloromethane T=20°C; 2 h;

1: Ag2O; Br2 / acetone / -10 °C 2: 89 percent / NaN3 / dimethylformamide / 6 h / 25 °C 3: 90 percent / LiBH4 / tetrahydrofuran; methanol / 1 h / 0 °C 4: 99 percent / H2 / Pd/C / methanol / 12 h / 20 °C / 760 Torr View Scheme