1: (S)-(-)-4-benzyl-2-oxazolidinone With n-butyllithium; triphenylemethane in tetrahydrofuran; hexane T=-78°C; 1 h; 2: 3-methyl-butyryl chloride in tetrahydrofuran; hexane T=-78 - 20°C; 2.5 h; 3: With potassium carbonate in tetrahydrofuran; hexane; water

4-(N,N-dimethlyamino)pyridine; dicyclohexyl-carbodiimide in dichloromethane T=20°C; Cooling with ice;

in hexane; toluene 1.) -40 deg C, irradiation, 5 h; 2.) -20 deg C, 29 h, in the dark;

1.1: lithium diisopropyl amide / tetrahydrofuran; hexane / -78 - -45 °C / |Inert atmosphere 1.2: 1 h / -45 - -20 °C 2.1: dihydrogen peroxide; LiOH*H2O; water / tetrahydrofuran / 0 - 25 °C 3.1: sulfuric acid; sodium tetrahydroborate / tetrahydrofuran / 0 - 20 °C 4.1: thionyl chloride / toluene; N,N-dimethyl acetamide / 2.5 h / 89 - 95 °C View Scheme

1: 94 percent / LIHMDS / tetrahydrofuran / -78 °C 2: 88 percent / OsO4; NMMO / 2-methyl-propan-2-ol; acetone; H2O 3: NaIO4; RuCl3*H2O / CCl4; acetonitrile; H2O / 6 h 4: (COCl)2 / dimethylformamide; toluene / 1 h 5: NEt3 / CH2Cl2 6: 100 percent / H2 / Pd/C / ethyl acetate 7: (COCl)2 / toluene; dimethylformamide / 1 h 8: Mg; BrCH2CH2Br / tetrahydrofuran / 20 °C 9: H2 / [Ru2Cl4((S)-BINAP)]NEt3 / methanol / 40 h / 40 °C / 37503 Torr 10: NEt3 / CH2Cl2 11: 85 percent / NaN3; 15-crown-6; DMPU View Scheme

1: 94 percent / LIHMDS / tetrahydrofuran / -78 °C 2: 88 percent / OsO4; NMMO / 2-methyl-propan-2-ol; acetone; H2O 3: NaIO4; RuCl3*H2O / CCl4; acetonitrile; H2O / 6 h 4: (COCl)2 / dimethylformamide; toluene / 1 h 5: NEt3 / CH2Cl2 6: 100 percent / H2 / Pd/C / ethyl acetate 7: (COCl)2 / toluene; dimethylformamide / 1 h 8: Mg; BrCH2CH2Br / tetrahydrofuran / 20 °C 9: H2 / [Ru2Cl4((S)-BINAP)]NEt3 / methanol / 40 h / 40 °C / 37503 Torr 10: NEt3 / CH2Cl2 11: 85 percent / NaN3; 15-crown-6; DMPU 12: 59 percent / 2-OH-pyridine; NEt3 13: H2; aq. HCl / Pd/C / methanol View Scheme

1: 81 percent / TiCl4, Et3N / CH2Cl2 / 60 h / 0 °C 2: 77 percent / H2O2, LiOH*H2O / H2O; tetrahydrofuran / 1 h / 0 °C 3: 75 percent / aq. HCl / acetic acid / 48 h / Heating 4: 87 percent / aq. NaOH / dioxane / 16 h View Scheme

1: 1.) diisopropylethylamine, dibutylboryl triflate (n-Bu2BOTf), 2.) N-bromosuccinimide (NBS) / 1.) CH2Cl2, a.) -78 deg C, 15 min, b.) 0 deg C, 1 h, 2.) -78 deg C, 1.25 h 2: tetramethylguanidinium azide (TMGA) / CH2Cl2 / 9 h / 25 °C 3: 96 percent / lithium hydroxide / tetrahydrofuran; H2O / 0.5 h / 0 °C 4: 99 percent / H2 / 10percent Pd/C / H2O; acetic acid / 3 h / 760 Torr View Scheme

1: (4R)-4-benzyl-3-(3-methyl-1-oxobutyl)-2-oxazolidinone With titanium tetrachloride in dichloromethane T=0°C; 0.166667 h; 2: With N-ethyl-N,N-diisopropylamine in dichloromethane T=0°C; 1 h; 3: chloromethyl benzyl ether in dichloromethane 16 h;

1: (4R)-4-benzyl-3-(3-methyl-1-oxobutyl)-2-oxazolidinone With titanium tetrachloride; N-ethyl-N,N-diisopropylamine in dichloromethane T=0°C; 1 h; 2: chloromethyl benzyl ether in dichloromethane T=0°C; 20 h;