A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene bridges (-CH2- units) are replaced by sulfur.

[1] 1,3-Dithianes are sometimes used as protecting group of carbonyl-containing compounds.

They form by treatment of the carbonyl compound with 1,3-propanedithiol under conditions that remove water from the system.

The protecting group can be removed with mercuric reagents, a process that exploits the high affinity of Hg(II) for thiolates.

It has no applications but traces occur as a product of degradations, e.g., cooking[3] coal pyrolysis.