1: With chloro-trimethyl-silane; 1,1,1,3,3,3-hexamethyl-disilazane; sodium iodide in acetonitrile T=0°C; 4 h; 2: With N-bromosuccinmide in tetrahydrofuran T=-18 - 23°C; 14 h;

1.1: lithium diisopropylamide / tetrahydrofuran / 1 h / -18 °C 1.2: 95 percent / oxalic acid / tetrahydrofuran; H2O / 0 - 27 °C 2.1: NaI; TMSCl; (TMS)2NH / acetonitrile / 4 h / 0 °C 2.2: 80 percent / N-bromosuccinimide / tetrahydrofuran / 14 h / -18 - 23 °C View Scheme

1.1: lithium diisopropylamide / tetrahydrofuran / 1 h / -18 °C 1.2: 95 percent / oxalic acid / tetrahydrofuran; H2O / 0 - 27 °C 2.1: NaI; TMSCl; (TMS)2NH / acetonitrile / 4 h / 0 °C 2.2: 80 percent / N-bromosuccinimide / tetrahydrofuran / 14 h / -18 - 23 °C View Scheme