triethylamine; trichlorophosphate in tetrahydrofuran T=-78 - 0°C; 1 h;

1: acetic anhydride / 2 h / 0 - 20 °C 2: triethylamine; trichlorophosphate / tetrahydrofuran / 1 h / -78 - 0 °C View Scheme

1: HClO4 / 48 h / 20 °C 2: acetic anhydride / formic acid / 5 h / 20 °C 3: trichlorophosphate; triethylamine / tetrahydrofuran / 2 h / -78 - 20 °C / |Inert atmosphere View Scheme

(i) KOtBu, THF, (ii) /BRN= 385801/; Multistep reaction;