1: 1.) oxalyl chloride, DMSO; 2.) triethylamine / 1.) CH2Cl2, -60- -50 deg C, 15 min; 2.) -60- -50 deg C, 5 min 2: 45 percent / LiCl, DBU / dimethylsulfoxide / 39 h / Ambient temperature 3: 1.) triethylsilane; 2.) 48 percent aq. HF / 1.) (PPh3)3RhCl / 1.) benzene, 70 deg C, 40 min; 2.) CH3CN, rt. 50 min 4: 39 percent / NaBH4 / methanol / 0.75 h / Ambient temperature 5: 85 percent / p-Ts-OH*H2O / benzene / 0.67 h / Ambient temperature View Scheme