Sulfolene

Sulfolene, or butadiene sulfone is a cyclic organic chemical with a sulfone functional group. It is the product of a (4+1) cycloaddition (or more technically a cheletropic reaction) between butadiene and sulfur dioxide.

Catalytic hydrogenation yields sulfolane, a solvent used in the petrochemical industry for the extraction of aromatics from hydrocarbon streams. In the laboratory it is used as a solid source of butadiene, into which it decomposes by a reverse cycloaddition. However, the sulfur dioxide that is generated as a side product may cause side reactions with acid-sensitive substrates.