Electrolysis of 3 (R= Phenyl) and NaBr in MeCN. A mixture of 3 (R'= phenyl, 218 mg, 1 mmol) and NaBr (129 mg, 1.25 mmol) in MeCN (20 mL) containing Et4NC104 (100 mg) was electrolyzed at 3 V (applied voltage), 4-3 mA/cm2, at 29-30" C for 2.5 h. After 2 X faraday of electricity was passed and the solvent was removed, chromatography (SiO?, hexanelbenzene) gave 4 (R'= phenyl, 11 mg, 4%) and recovered 3 (195 mg, 89%). ...