1: in tetrahydrofuran T=-78°C; 2 h; 2: With hydrogenchloride in tetrahydrofuran; water

1.1: n-butyllithium / tetrahydrofuran / 1 h / -70 °C 1.2: 62 percent / tetrahydrofuran / 2 h / -70 °C 2.1: 26 percent / tetrahydrofuran / -70 - 20 °C View Scheme

in tetrahydrofuran T=-70 - 20°C;

magnesium 1.) THF, 2.) -78 deg C; Yield given. Multistep reaction;

1: tert-butyl (4-oxo-4-phenyl-butyl)-carbamate With formic acid T=20°C; 12 h; 2: With sodium hydrogencarbonate 6 h; 3: di-tert-butyl dicarbonate With Ru(Η6-cymene)(MsDPEN)(BArF); hydrogen in dichloromethane T=40°C; P=38002.6 Torr; 10 h; Inert atmosphereAutoclave; optical yield given as percent ee;

trifluoroacetic acid in dichloromethane T=20°C; 1.5 h;

sodium hydroxide; trifluoroacetic acid 1.) RT, 3 h, 2.) 0 deg C; Yield given. Multistep reaction;