1: With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 1 h; Inert atmosphere; 2: With N-bromosuccinmide in tetrahydrofuran T=-78°C; 2 h; Inert atmosphere; 3: With 1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran T=-78 - 20°C; Inert atmosphere;

pyridinium hydrobromide perbromide in tetrahydrofuran 1 h; 0 deg C to rt;

1: 98 percent / Br2 / CHCl3 / 0.75 h / 0 °C 2: 82 percent / LDA / tetrahydrofuran / 4 h / -78 °C 3: 70percent aq. perchloric acid / tetrahydrofuran / 1.25 h 4: 80 percent / pyridinium bromide perbromide / tetrahydrofuran / 1 h / 0 deg C to rt View Scheme

1: 82 percent / LDA / tetrahydrofuran / 4 h / -78 °C 2: 70percent aq. perchloric acid / tetrahydrofuran / 1.25 h 3: 80 percent / pyridinium bromide perbromide / tetrahydrofuran / 1 h / 0 deg C to rt View Scheme

1: 70percent aq. perchloric acid / tetrahydrofuran / 1.25 h 2: 80 percent / pyridinium bromide perbromide / tetrahydrofuran / 1 h / 0 deg C to rt View Scheme

1: ammonium cerium (IV) nitrate / water; acetonitrile / 1 h / 0 °C 2: sodium azide / tetrahydrofuran; water / 1 h / 20 °C 3: caesium carbonate / toluene / 1 h / 20 °C / Inert atmosphere 4: potassium hydroxide / methanol; water / 1 h / 20 °C 5: ammonium cerium (IV) nitrate; sodium hydrogencarbonate / tetrahydrofuran / 1 h / 20 °C / Inert atmosphere 6: boron tribromide / dichloromethane / 1.5 h / -78 - -20 °C / Inert atmosphere View Scheme