1: 41 percent Chromat. / NH4OH / 2-methyl-propan-2-ol / 4 h / 10 °C / Irradiation 2: 1.) BH3, 2.) Br2, NaOMe / 1.) a) THF, 0 deg C, 30 min, b) 25 deg C, 30 min, 2.) THF, MeOH, 20-25 deg C 3: 4 percent Chromat. / NH4OH / 2-methyl-propan-2-ol / 6 h / 10 °C / Irradiation View Scheme

ammonium hydroxide in tert-butyl alcohol T=10°C; 4 h; Irradiation;

1: 41 percent Chromat. / NH4OH / 2-methyl-propan-2-ol / 4 h / 10 °C / Irradiation 2: 85 percent / 48percent HBr / 9 h / 59 °C 3: 27 percent Chromat. / NH4OH / methanol / 6 h / 10 °C / Irradiation View Scheme

ammonium hydroxide T=10°C; 1.5 h; Irradiation;

1: 41 percent Chromat. / NH4OH / 2-methyl-propan-2-ol / 4 h / 10 °C / Irradiation 2: 1.) BH3, 2.) Br2, NaOMe / 1.) a) THF, 0 deg C, 30 min, b) 25 deg C, 30 min, 2.) THF, MeOH, 20-25 deg C 3: 5 percent Chromat. / NH4OH / 2-methyl-propan-2-ol / 6 h / 10 °C / Irradiation View Scheme

1: 41 percent Chromat. / NH4OH / 2-methyl-propan-2-ol / 4 h / 10 °C / Irradiation 2: 85 percent / 48percent HBr / 9 h / 59 °C View Scheme