Complex sentence: Under free radical conditions the direction of the addition can be reversed, as is used commericially for the synthesis of 1-bromoalkanes, precursors to tertiary amines and quaternary ammonium salts.
Split into simpler sentences: Under free radical conditions, the direction of the addition can be reversed. Free-radical addition is used commercially for the synthesis of 1-bromoalkanes, precursors to tertiary amines and quaternary ammonium salts.