lithium aluminium tetrahydride in diethyl ether 3.5 h; Heating;

1: (1R,3S)-5-oxo-1-(1-phenyl-ethyl)-pyrrolidine-3-carboxylic acid methyl ester With lithium aluminium tetrahydride in tetrahydrofuran Heating; 2: With hydrogen; palladium dihydroxide in methanol T=20°C; 3: benzyl chloroformate With potassium carbonate in tetrahydrofuran; water T=0°C; Further stages.;

1.1: lithium aluminium tetrahydride / CPME / 1.25 h / 0 - 20 °C / Inert atmosphere 1.2: 0 °C 2.1: 1H-imidazole / N,N-dimethyl-formamide / 0 - 20 °C 3.1: 1-chloroethyl chlorocarbonate / 1,2-dichloro-ethane / 5 h / Reflux 3.2: 3 h / Reflux 3.3: 3 h / 0 °C View Scheme

1: 85 percent / lithium aluminum hydride / diethyl ether / 3.5 h / Heating 2: 92 percent / thionyl chloride / CHCl3 / 2 h / Heating 3: 67 percent / tricaprylmethylammonium chloride / H2O / 48 h / 100 °C 4: 1.) acetyl chloride, 2.) water / 1.) RT, 48 h, 2.) 1 h 5: 62 percent / H2 / 10percent Pd-C / methanol / 2205.2 Torr View Scheme