1: 84 percent / K2CO3 / methanol; H2O / 3 h 2: Et3N / tetrahydrofuran / 0.25 h / 20 °C 3: 0.081 g / DMAP / tetrahydrofuran; toluene / 3.5 h / 20 °C 4: 99 percent / HF*pyridine / tetrahydrofuran / 2 h / 25 °C 5: 49 percent / 3,3-dimethyldioxirane / CH2Cl2; acetone / 2 h / -50 - -30 °C View Scheme

1: 84 percent / K2CO3 / methanol; H2O / 3 h 2: Et3N / tetrahydrofuran / 0.25 h / 20 °C 3: 0.081 g / DMAP / tetrahydrofuran; toluene / 3.5 h / 20 °C 4: 99 percent / HF*pyridine / tetrahydrofuran / 2 h / 25 °C View Scheme