1: 75 percent / CF3COOH / CH2Cl2 / 48 h / 20 °C 2: 97 percent / PPh3; DEAD / 0.5 h 3: 65 percent / MeNHNH2 / tetrahydrofuran / 70 h / 20 °C View Scheme

trifluoroacetic acid in dichloromethane T=20°C; Deacetylation; 48 h;

water; hydrazine in ethanol T=-20°C; 2 h;