hydrogen; palladium on activated charcoal in methanol; ethyl acetate P=760 Torr;

1: Et3N / CH2Cl2 / 0.75 h / -40 °C 2: BF3*Et2O / CH2Cl2 / 12 h / -40 - 20 °C 3: 98 percent / H2 / Pd/C / ethyl acetate; methanol / 760 Torr View Scheme

1: BF3*Et2O / CH2Cl2 / 12 h / -40 - 20 °C 2: 98 percent / H2 / Pd/C / ethyl acetate; methanol / 760 Torr View Scheme

1: ethyl acetate; H2O / 2 h / 0 °C 2: BF3*Et2O / CH2Cl2 / 12 h / -40 - 20 °C 3: 98 percent / H2 / Pd/C / ethyl acetate; methanol / 760 Torr View Scheme

1: With N-tert-butoxycarbonyl-D-phenylalanine in hexane; ethyl acetate 2: With sodium hydrogencarbonate in dichloromethane 0.166667 h;

1.1: L-Boc-Phe-OH / ethyl acetate; hexane 1.2: aq. NaHCO3 / CH2Cl2 / 0.17 h 2.1: 97 percent / NaHCO3 / ethyl acetate; H2O / 2 h / 20 °C 3.1: aq. CAN / acetonitrile / 0 °C 4.1: 0.652 g / DMAP / acetonitrile / 0 - 20 °C View Scheme