1: 57 percent / SeO2, pyridine N-oxide / dioxane / 2 h / Heating 2: 91 percent / DIPEA, DMAP / CH2Cl2 / 0.67 h / -78 °C 3: 95 percent / K2CO3 / methanol / 2 h 4: 90 percent / Dess-Martin reagent / CH2Cl2 5: 41 percent / L-Selectride / tetrahydrofuran / -78 - 20 °C View Scheme

1: 57 percent / SeO2, pyridine N-oxide / dioxane / 2 h / Heating 2: 91 percent / DIPEA, DMAP / CH2Cl2 / 0.67 h / -78 °C 3: 95 percent / K2CO3 / methanol / 2 h 4: 90 percent / Dess-Martin reagent / CH2Cl2 View Scheme