1: 70 percent / aq. KOH / methanol / Heating 2: 1.) HgO, MgSO4, 2.) Br2 / 1.) CH2Cl2, reflux, 15 min, 2.) CH2Cl2, reflux, 3.5 h 3: 1.) THF, pentane, -78 deg C, 5 min, 2.) THF, pentane, from -78 deg C to RT View Scheme

potassium hydroxide in methanol Heating;

1: LAH 2: activated dimethylsulfoxide 3: bis Wittig olefination View Scheme