chloro-trimethyl-silane; potassium hydride 1.) tetrahydrofuran, room t., 15 h, 0 degC, 15 min; 2.) from -78 to 50 degC over 1 h, 50 degC, 1 h; Yield given. Multistep reaction;

(i) BCl3, (ii) H2O; Multistep reaction;