1: (S)-(-)-4-benzyl-2-oxazolidinone With sodium hydride in tetrahydrofuran T=0°C; 1.16667 h; 2: propionyl chloride in tetrahydrofuran T=0 - 20°C;

electrogenerated base from 2-pyrrolidone; N(Et)4ClO4 in acetonitrile T=20°C;

4-(N,N-dimethlyamino)pyridine; dicyclohexyl-carbodiimide in dichloromethane T=20°C; 6 h;

4-(N,N-dimethlyamino)pyridine; triethylamine in tetrahydrofuran 12 h; Ambient temperature;

1: 71 percent / n-BuLi / hexane; tetrahydrofuran / 1.) -78 deg C, 30 min, 2.) -78 deg C to room temp., 30 min 2: 57 percent / NaHMDSA / tetrahydrofuran / 1.) -78 deg C, 30 min, 2.) -78 deg C, 5 h 3: LiOH*H2O, 30percent aq. H2O2 / tetrahydrofuran / 5 h 4: 64 percent / n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 30 min, 2.) -78 deg C to 21 deg C, 30 min View Scheme

(S)-HBTM; N-ethyl-N,N-diisopropylamine in chloroform-d1 T=50°C; 3 h; Inert atmosphere;

1: 75 percent / K2CO3 / 2 h / 135 °C 2: 98 percent / n-BuLi / tetrahydrofuran / 1.25 h / -78 - 20 °C View Scheme

1: 51 percent / LiAlH4 / tetrahydrofuran / 15 h / Heating 2: 75 percent / K2CO3 / 2 h / 135 °C 3: 98 percent / n-BuLi / tetrahydrofuran / 1.25 h / -78 - 20 °C View Scheme

diethylzinc in tetrahydrofuran; toluene T=20°C; Title compound not separated from byproducts;

1: LiOH*H2O, 30percent aq. H2O2 / tetrahydrofuran / 5 h 2: 64 percent / n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 30 min, 2.) -78 deg C to 21 deg C, 30 min View Scheme