Chemistry of acetylenic ethers 102: Reaction of di(1‐alkynyl) sulfides with sodium sulfide, selenide and telluride. Formation of 1,4‐dithiins, 1,4‐thiaselenins and 1,4‐thiatellurins

Abstract Interaction between di(1‐alkynyl) sulfides (1) and sodium sulfide, selenide or telluride in mixtures of liquid ammonia and methanol or dimethylformamide and methanol gives 1,4‐dithiins (2), 1,4‐thiaselenins (3) and 1,4‐thiatellurins (4).