1.1: (+)-diethyl tartrate; Ti(O-i-Pr)4; tert-butylhydroperoxide 1.2: triethylamine; 4-(dimethylamino)pyridine 1.3: p-toluenesulfonic acid / tetrahydrofuran; H2O 2.1: p-toluenesulfonic acid / acetone / 20 °C 3.1: tetrabutylammonium fluoride / tetrahydrofuran / 20 °C View Scheme

1: 94 percent / imidazole / tetrahydrofuran / 24 h / Ambient temperature 2: 83 percent / K2CO3 / H2O; methanol / 2 h / Ambient temperature 3: 91 percent / p-TsOH / CH2Cl2 / 12 h / Ambient temperature 4: 94 percent / TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: 83 percent / K2CO3 / H2O; methanol / 2 h / Ambient temperature 2: 91 percent / p-TsOH / CH2Cl2 / 12 h / Ambient temperature 3: 94 percent / TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: Ti(O-i-Pr)4 / CH2Cl2 / 3 h / 20 °C 2: imidazole / dimethylformamide / 3 h / 20 °C 3: Cs2CO3 / methanol; H2O / 3 h / 20 °C 4: p-toluenesulfonic acid / acetone / 20 °C 5: tetrabutylammonium fluoride / tetrahydrofuran / 20 °C View Scheme

1: 90 percent / CHCl3 / 3 h / -20 - 0 °C 2: 94 percent / imidazole / tetrahydrofuran / 24 h / Ambient temperature 3: 83 percent / K2CO3 / H2O; methanol / 2 h / Ambient temperature 4: 91 percent / p-TsOH / CH2Cl2 / 12 h / Ambient temperature 5: 94 percent / TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: imidazole / dimethylformamide / 3 h / 20 °C 2: Cs2CO3 / methanol; H2O / 3 h / 20 °C 3: p-toluenesulfonic acid / acetone / 20 °C 4: tetrabutylammonium fluoride / tetrahydrofuran / 20 °C View Scheme

1: Cs2CO3 / methanol; H2O / 3 h / 20 °C 2: p-toluenesulfonic acid / acetone / 20 °C 3: tetrabutylammonium fluoride / tetrahydrofuran / 20 °C View Scheme

1: p-TsOH / CH2Cl2 / 8 h / Ambient temperature 2: 15percent NaOH / tetrahydrofuran; H2O / Ambient temperature View Scheme

Multistep reaction.;