1: I2, 4percent aq. NaHCO3 / CH2Cl2 / 10 h / Ambient temperature 2: 1,5-diazabicyclo<4.3.0>non-5-ene / 10 h / Ambient temperature 3: 84 percent / 1) O3, 2) Me2S / CH2Cl2; methanol / 1) -78 deg C, 45 min, 2) up to r. t., 12 h View Scheme