1: 66 percent / K2CO3 / acetone / 5 h / Heating 2: 96 percent / p-TSA; m-CPBA / CH2Cl2 / 4 h / 0 - 20 °C 3: 94 percent / triethylamine / CH2Cl2; methanol / 1 h / 20 °C View Scheme

1: HClO2; NaH2PO4; DMS / tetrahydrofuran; H2O / 2 h / 20 °C 2: 173.3 g / tetrahydrofuran; methanol View Scheme

potassium carbonate in acetone 5 h; Heating;