1: 21 percent Chromat. / trifluoroacetic acid (TFA), trifluoromethanesulphonic acid (TFSA) / 4 h / -30 °C 2: 1.) trifluoroacetic anhydride (TFAA) / 1.) CH2Cl2, -60 deg C, 2.) a) -60 deg C, 2 h, b) from -60 deg C to RT View Scheme

trifluoroacetic anhydride 1.) CH2Cl2, -60 deg C, 2.) a) -60 deg C, 2 h, b) from -60 deg C to RT; Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;