N-bromosuccinmide; tetra(n-butyl)ammonium hydroxide; potassium hydrogencarbonate in dichloromethane; water T=25°C; 0.5 h;

bromine in dichloromethane T=0°C; 0.5 h; Yield given. Yields of byproduct given;

1: 89.7 percent / tetrabutylammonium fluoride trihydrate / tetrahydrofuran / 3 h / 20 °C 2: 24.4 percent / N-bromosuccinimide; KHCO3; aq. Bu4NOH / CH2Cl2 / 0.5 h / 20 °C View Scheme

1: 84 percent / 1.) lithium diisopropylamide / tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) 0 deg C, 1 h, 2.) 25 deg C, 4 h 2: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / 25 °C 3: 89 percent / N-bromosuccinimide, KHCO3, tetrabutylammonium hydroxide / CH2Cl2; H2O / 0.5 h / 25 °C View Scheme

1: Br2 / tetrahydrofuran / 0.5 h / 0 °C 2: tetrabutylammonium fluoride / tetrahydrofuran / 4 h / 0 °C View Scheme