acetic anhydride; triethylamine in chloroform 1.) 0 deg C, 30 min, 2.) r. t., 60 min;

1: 95 percent / Br2 / various solvent(s) / 1.) reflux, 1 h, 2.) r. t., 18 h 2: 53 percent / ethyl-N,N-diisopropylamine / CHCl3 / 44 h / Heating 3: 70 percent / 30percent H2O2 / methanol / 168 h / Ambient temperature 4: 53 percent / Et3N, Ac2O / CHCl3 / 1.) 0 deg C, 30 min, 2.) r. t., 60 min View Scheme

1: 70 percent / 30percent H2O2 / methanol / 168 h / Ambient temperature 2: 53 percent / Et3N, Ac2O / CHCl3 / 1.) 0 deg C, 30 min, 2.) r. t., 60 min View Scheme

1: 53 percent / ethyl-N,N-diisopropylamine / CHCl3 / 44 h / Heating 2: 70 percent / 30percent H2O2 / methanol / 168 h / Ambient temperature 3: 53 percent / Et3N, Ac2O / CHCl3 / 1.) 0 deg C, 30 min, 2.) r. t., 60 min View Scheme

in tert-butyl alcohol Ambient temperature;