Direct access to thieno[3,4-b]thiophenes via elemental sulfur-promoted sulfurative tetramerization of acetophenones.

Thieno[3,4-b]thiophene cores could be conveniently obtained via one-pot sulfurative tetramerization of acetophenones using a ternary system comprised of elemental sulfur, a base and DMSO under simple heating conditions. The structure of the products was verified by X-ray crystallography.