1: 1.) DBU, 2.) ozone / 1.) 150 min, 90 deg C, 2.) CH2Cl2/methanol, -78 deg C 2: 86 percent / 0.15 M aqueous LiOH / tetrahydrofuran / 4 h / Heating 3: 1.) pyridinium chlorochromate, sodium acetate, 2.) 0.15 M aqueous LiOH / 1.) CH2Cl2, 1 h, room temperature, 2.) THF, 5 min, room temperature View Scheme