Propane-1,3-dithiol
1,3-Propanedithiol is the chemical compound with the formula HSCHCHCHSH. This dithiol is a useful reagent in organic synthesis. This liquid, which is readily available commercially, has an intense stench. Use in organic synthesis. 1,3-Propanedithiol is mainly used for the protection of aldehydes and ketones via their reversible formation of dithianes. A prototypical reaction is its formation of 1,3-dithiane from formaldehyde. The reactivity of this dithiane illustrates the concept of umpolung. Alkylation gives thioethers, e.g. 1,5-dithiacyclooctane. The unpleasant odour of 1,3-propanedithiol has encouraged the development of alternative reagents that generate similar derivatives. 1,3-Propanedithiol  is used in the synthesis of tiapamil. Use in inorganic synthesis. 1,3-Propanedithiol reacts with metal ions to form chelate rings. Illustrative is the synthesis of the derivative diiron propanedithiolate hexacarbonyl upon reaction with triiron dodecacarbonyl: Safety. The stench of 1,3-propanedithiol can be neutralized with bleach.