1: 95 percent / NaI / acetone / 24 h / Heating 2: 1) t-BuLi / 1) Et2O, -78 deg C, 1 h 3: 1) oxalyl chloride, DMSO, 2) Et3N / 1) CH2Cl2, -60 deg C, 15 min, 2) 5 min View Scheme

dipyridinium dichromate; magnesium Multistep reaction;