A simple synthesis of the new heterocyclic compounds 1,4‐oxathiin and 3,5‐dimethyl‐1,4‐oxathiin

Sulfur dichloride adds to vinylic ethers to give 2,6-dichloro-1,4-oxathianes. Dehydro-halogenation of these products leads to the hitherto unknown heterocyclic compounds 1,4-oxathiin 6 and 3,5-dimethyl-1,4-oxathiin 7 in good overall yields.