A dithiane is a compound whose molecule has a six-membered ring containing two sulfur atoms. Dithianes are classified into three classes.
Dithiane 1 and its derivates are called 1,2-dithianes.
Dithiane 2 and its derivates are called 1,3-dithianes.
Dithiane 3 and its derivatives are called 1,4-dithianes.
The three classes of dithianes are different from one another functionally. A 1,2-dithiane is a disulfide. A 1,3-dithiane is either a cyclic thioacetal or a cyclic thioketal (see acyl anion equivalent). The molecule of a 1,4-dithiane contains two thioether groups.