1: H2, triethylamine / 10percent Pd/C / tetrahydrofuran / Ambient temperature; atmospheric pressure 2: 1) trifluoroacetic acid / 1) 30 min, 2) methylene chloride, r.t., 30 min, then 40 deg C, 1 h View Scheme

1: TFA / 0.05 h / 50 °C 2: H2O / 2 h / 0 - 20 °C View Scheme

1: H2SO4 / H2O / 14 h / 20 °C 2: TFA / 0.05 h / 50 °C 3: H2O / 2 h / 0 - 20 °C View Scheme

in water T=0 - 20°C; 2 h;

1: Zn dust, sodium acetate, glacial acetic acid / H2O / 1 h / Heating 2: 84 percent / diborane / tetrahydrofuran 3: 94 percent / thionyl chloride, pyridine / CH2Cl2 / 1.5 h / Heating 4: 1.) TFA, 2.) trimethyl orthoformate / 1.) 35 deg C, 10 min, 2.) 0-20 deg C, 2 h View Scheme

1: 94 percent / thionyl chloride, pyridine / CH2Cl2 / 1.5 h / Heating 2: 1.) TFA, 2.) trimethyl orthoformate / 1.) 35 deg C, 10 min, 2.) 0-20 deg C, 2 h View Scheme

1: 84 percent / diborane / tetrahydrofuran 2: 94 percent / thionyl chloride, pyridine / CH2Cl2 / 1.5 h / Heating 3: 1.) TFA, 2.) trimethyl orthoformate / 1.) 35 deg C, 10 min, 2.) 0-20 deg C, 2 h View Scheme

1: 52 percent / potassium carbonate / acetone / 1 h / Heating 2: Zn dust, sodium acetate, glacial acetic acid / H2O / 1 h / Heating 3: 84 percent / diborane / tetrahydrofuran 4: 94 percent / thionyl chloride, pyridine / CH2Cl2 / 1.5 h / Heating 5: 1.) TFA, 2.) trimethyl orthoformate / 1.) 35 deg C, 10 min, 2.) 0-20 deg C, 2 h View Scheme

trifluoroacetic acid 1) 30 min, 2) methylene chloride, r.t., 30 min, then 40 deg C, 1 h; Multistep reaction;

trifluoroacetic acid; trimethyl orthoformate 1.) 35 deg C, 10 min, 2.) 0-20 deg C, 2 h; Yield given. Multistep reaction;