1: 48percent HF / acetonitrile; CH2Cl2 / 4 h 2: 1.) LDA / 1.) THF, -50 deg C, 40 min; -30 deg C, 40 min, 2.) HMPA, -50 deg C, 1 h; -20 deg C, 2 h; 0 deg C, 1 h 3: 1 N KOH / ethanol / 4 h / 50 °C 4: benzenesulfonyl chloride, pyridine / 0 °C 5: H2 / 10percent Pd-C / ethyl acetate View Scheme

1: 48percent HF / acetonitrile; CH2Cl2 / 4 h 2: 1.) LDA / 1.) THF, -50 deg C, 40 min; -30 deg C, 40 min, 2.) HMPA, -50 deg C, 1 h; -20 deg C, 2 h; 0 deg C, 1 h 3: 1 N KOH / ethanol / 4 h / 50 °C 4: benzenesulfonyl chloride, pyridine / 0 °C 5: H2 / 10percent Pd-C / ethyl acetate 6: 85.8 percent / PPh3, diethyl azodicarboxylate / tetrahydrofuran / Ambient temperature View Scheme

1: 48percent HF / acetonitrile; CH2Cl2 / 4 h 2: 1.) LDA / 1.) THF, -50 deg C, 40 min; -30 deg C, 40 min, 2.) HMPA, -50 deg C, 1 h; -20 deg C, 2 h; 0 deg C, 1 h 3: 1 N KOH / ethanol / 4 h / 50 °C 4: benzenesulfonyl chloride, pyridine / 0 °C 5: H2 / 10percent Pd-C / ethyl acetate View Scheme