Synthesis of 2-heterosubstituted 1,3-oxathianes and their reaction with sec- butyllithium

A series of 2-heterosubstituted 1,3-oxathianes were synthesized and their reactivity toward a strong base, sec-butyllithium, was studied. It was shown that sec-butyllithium attacked 2-heterosubstituted 1,3-oxathianes in three different ways depending upon the heteroatom at C-2; the removal of the proton at C-2, the nucleophilic attack at the heteroatom, or the nucleophilic attack at C-2 took place.