trifluoroacetic acid in dichloromethane T=20°C; 15 h;

penicillin acylase in various solvent(s) T=25°C; 12 h; Yield given. Yields of byproduct given;

1: HCl / Heating 2: Et3N, DMAP / CH2Cl2 3: LiOH, H2O / methanol 4: penicillin acylase / various solvent(s) / 12 h / 25 °C View Scheme

1: Et3N, DMAP / CH2Cl2 2: LiOH, H2O / methanol 3: penicillin acylase / various solvent(s) / 12 h / 25 °C View Scheme

4-(N,N-dimethlyamino)pyridine; triethylamine in dichloromethane penicillin acylase, pH 7.5, phosphate buffer, 25 deg C, 12 h;

1: 87 percent / H2; acetic acid / Pd(OH)2/C / methanol; H2O / 24 h / 20 °C / 760.05 Torr 2: 97 percent / trifluoroacetic acid / CH2Cl2 / 15 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 88 percent / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: 87 percent / H2; acetic acid / Pd(OH)2/C / methanol; H2O / 24 h / 20 °C / 760.05 Torr 3.1: 97 percent / trifluoroacetic acid / CH2Cl2 / 15 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 95 percent / tetrahydrofuran; hexane / -78 - 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.2: 88 percent / tetrahydrofuran; hexane / 3 h / -78 °C 3.1: 87 percent / H2; acetic acid / Pd(OH)2/C / methanol; H2O / 24 h / 20 °C / 760.05 Torr 4.1: 97 percent / trifluoroacetic acid / CH2Cl2 / 15 h / 20 °C View Scheme