1: 93 percent / 2,6-lutidine / CH2Cl2 / 0.5 h / -30 °C 2: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1.5 h / 25 °C 3: 99 percent / HF*pyridine / tetrahydrofuran / 2 h / 25 °C 4: 49 percent / 3,3-dimethyldioxirane / CH2Cl2; acetone / 2 h / -50 - -30 °C View Scheme

1: 93 percent / 2,6-lutidine / CH2Cl2 / 0.5 h / -30 °C 2: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1.5 h / 25 °C 3: 99 percent / HF*pyridine / tetrahydrofuran / 2 h / 25 °C View Scheme