1: 40 percent / (2-chloro-1,1,2-trifluoroethyl)diethylamine / acetonitrile / 1.) room temp., 1 h, 2.) reflux, 3 h 2: 1.) BuLi / 1.) THF, 0 deg C, 30 min, 2.) 0 deg C, 30 min; room temp., 1 h 3: 70 percent / KOH / methanol / 7 h / -30 °C 4: 1.) 6N HCl, 2.) Et3N / 1.) 120 deg C, 5 h, 2.) 80 deg C, 2 h View Scheme

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;

1: 40 percent / (2-chloro-1,1,2-trifluoroethyl)diethylamine / acetonitrile / 1.) room temp., 1 h, 2.) reflux, 3 h 2: 1.) BuLi / 1.) THF, 0 deg C, 30 min, 2.) 0 deg C, 30 min; room temp., 1 h 3: 70 percent / KOH / methanol / 7 h / -30 °C 4: 1.) 6N HCl, 2.) Et3N / 1.) 120 deg C, 5 h, 2.) 80 deg C, 2 h View Scheme