1: (2R,3R)-2-benzylamino-3-(4-methylsulfonylphenyl)-propane-1,3-diol With hydrogenchloride; hydrogen; palladium on activated charcoal in ethanol T=20°C; 2 h; 2: dichloroacetic acid ethyl ester With triethylamine in methanol T=30°C; 6 h; Further stages.;

triethylamine in methanol T=30°C; 8 h; Inert atmosphere;

3-chloro-benzenecarboperoxoic acid in tetrahydrofuran

boron tribromide in dichloromethane T=-78 - -20°C; 10 h;

1: (4R,5R)-4-hydroxymethyl-5-lt;4-(methylsulphonyl)phenylgt;-2-oxazolidinone With sodium hydroxide in methanol; water T=25°C; 2: dichloroacetic acid methyl ester T=90°C; 3 h;

dihydrogen peroxide; acetic acid; sodium nitrite in hydrogenchloride; methanol; water

1: With sodium hydride in dichloromethane T=0 - 20°C; 4 h; 2: With boron trifluoride diethyl etherate in dichloromethane T=-78 - 20°C; 4 h;

1: 94 percent / Et3N 2: 88 percent / m-CPBA View Scheme

1.1: 65 percent / sodium hydroxide; tert-butyl hypochlorite; potassium osmate / ethyldiisopropylamine / propan-1-ol; H2O / 3 h / 25 °C 2.1: NaOH / methanol; H2O / 25 °C 2.2: 77 percent / 3 h / 90 °C View Scheme

1.1: Mg / tetrahydrofuran / 0.5 h / 0 - 20 °C 1.2: 96 percent / tetrahydrofuran / 2 h / 0 - 25 °C 2.1: 95 percent / oxone / tetrahydrofuran; methanol; H2O / 0 - 25 °C 3.1: 43 percent / Ti(O-iPr)4; (+)-diisopropyl tartrate; tert-butyl hydroperoxide / molecular sieves 4 Angstroem / CH2Cl2 / 24 h / -20 °C 4.1: CH2Cl2 / 2 h / 0 - 25 °C 4.2: 86 percent / potassium carbonate / methanol; H2O / 18 h / 0 - 25 °C 5.1: 65 percent / sodium hydroxide; tert-butyl hypochlorite; potassium osmate / ethyldiisopropylamine / propan-1-ol; H2O / 3 h / 25 °C 6.1: NaOH / methanol; H2O / 25 °C 6.2: 77 percent / 3 h / 90 °C View Scheme