1: NaClO2, NaH2PO4*H2O / various solvent(s); 2-methyl-propan-2-ol; H2O / 1.) 0 deg C, 3 h, 2.) room temp., 30 min 2: 48percent HF / acetonitrile / 5 h / Ambient temperature 3: benzenesulfonyl chloride, pyridine / 0 °C 4: H2 / 10percent Pd-C / ethyl acetate View Scheme

1: NaClO2, NaH2PO4*H2O / various solvent(s); 2-methyl-propan-2-ol; H2O / 1.) 0 deg C, 3 h, 2.) room temp., 30 min 2: 48percent HF / acetonitrile / 5 h / Ambient temperature 3: benzenesulfonyl chloride, pyridine / 0 °C 4: H2 / 10percent Pd-C / ethyl acetate 5: 85.8 percent / PPh3, diethyl azodicarboxylate / tetrahydrofuran / Ambient temperature View Scheme

1: NaClO2, NaH2PO4*H2O / various solvent(s); 2-methyl-propan-2-ol; H2O / 1.) 0 deg C, 3 h, 2.) room temp., 30 min 2: 48percent HF / acetonitrile / 5 h / Ambient temperature 3: benzenesulfonyl chloride, pyridine / 0 °C 4: H2 / 10percent Pd-C / ethyl acetate View Scheme