in dichloromethane T=0 - 23°C; 2 h;

1.1: acetic acid / dichloromethane / 3 h / 0 - 23 °C 1.2: 12 h / 23 °C 2.1: hydrogen / palladium(II) oxide hydrate / ethanol; tetrahydrofuran / 6 h / 23 °C / 760.05 Torr / Inert atmosphere 3.1: dichloromethane / 2 h / 0 - 23 °C View Scheme

1: hydrogen / palladium(II) oxide hydrate / ethanol; tetrahydrofuran / 6 h / 23 °C / 760.05 Torr / Inert atmosphere 2: dichloromethane / 2 h / 0 - 23 °C View Scheme

trifluoroacetic acid T=20°C; 2 h;