1: 1.) triethylamine, ethyl chloroformate, 2.) tetramethylguanidinium azide / 1.) THF, 0 deg C, 1 h, 2.) chloroform, 0 deg C, 2.5 h 2: 90 percent / benzene / Heating View Scheme

1: LiI, 2,6-lutidine / 3 h / Heating 2: 1.) triethylamine, ethyl chloroformate, 2.) tetramethylguanidinium azide / 1.) THF, 0 deg C, 1 h, 2.) chloroform, 0 deg C, 2.5 h 3: 90 percent / benzene / Heating View Scheme