1: 1.) tert-butyllithium / 1.) THF, pentane, -100 deg C, 10 min , then to -70 deg C 2.) THF, to 0 deg C 2: 86 percent / 50 percent aq. acetic acid / 60 °C 3: 91 percent / trifluoroacetic anhydride, pyridine / CH2Cl2 / Ambient temperature View Scheme

1: 1.) tert-butyllithium / 1.) THF, pentane, -100 deg C, 10 min , then to -70 deg C 2.) THF, to 0 deg C 2: 86 percent / 50 percent aq. acetic acid / 60 °C View Scheme

1: 1.) tert-butyllithium / 1.) THF, pentane, -100 deg C, 10 min , then to -70 deg C 2.) THF, to 0 deg C 2: 86 percent / 50 percent aq. acetic acid / 60 °C 3: 79 percent / HO3SONO, H2O / CH2Cl2 / Ambient temperature View Scheme