1: pentafluorophenyl phosphorodichloridate With triethylamine; phenol in dichloromethane T=20°C; 0.5 h; 2: alanine isopropyl ester hydrochloride With triethylamine in dichloromethane T=0°C; 1 h;

triethylamine in dichloromethane T=0 - 20°C; Inert atmosphere;

1: alanine isopropyl ester hydrochloride With triethylamine in dichloromethane T=-70°C; 0.25 h; 2: phenylphosphoric acid dichloride in dichloromethane T=-70 - 0°C; 4.5 h; 3: 2,3,4,5,6-pentafluorophenol in dichloromethane T=0°C; 4.33333 h; optical yield given as percent de;

1: β-D-2'-deoxy-2'-α-F-2'-β-C-methyluridine With 1,1-dimethylethylmagnesium chloride in tetrahydrofuran T=-5 - 20°C; 2: (S)-2-[(S)-(2,3,4,5,6-pentafluoro-phenoxy)-phenoxy-phosphorylamino]propionic acid isopropyl ester in tetrahydrofuran T=-5 - 5°C; optical yield given as percent de;