1: 92 percent / BBr3 / CH2Cl2; hexane / 1.) -78 deg C, 3 h; 2.) room temp., 20 h 2: 1.) NaH / 1.) DMF, room temp., 30 min; 2.) 1 h 3: 61 percent Chromat. / DDQ / toluene / 4 h / Heating View Scheme

Multi-step reaction with 4 steps 1: 92 percent / BBr3 / CH2Cl2; hexane / 1.) -78 deg C, 3 h; 2.) room temp., 20 h2: 1.) NaH / 1.) DMF, room temp., 30 min; 2.) 1 h3: 61 percent Chromat. / DDQ / toluene / 4 h / Heating4: 100 percent / chlorotrimethylsilane, tetra-n-butylammonium bromide / CD2Cl2 / 1.) 0 deg C, 1 h; 2.) room temp., 30 min