In pursuit of the elusive trithia[1.1.1]propellane: Synthesis of potential 1,3-dithietane precursors

High-level ab initio calculations predicted the strained three-membered trithia[1.1.1]propellane 1a (X=Y=Z=S) to be a tightly-bound molecule which should be experimentally accessible. In analogy to the successful synthesis of'the [1.1.1] propellane, our synthesis strategy focused on the attempted preparation of 1,3-dihalo-trithia-bicyclo[1.1.1] pentanes 2 , to serve as a precursor for the target molecule. However, 1a proved to be unattainable via the planned strategy beyond the stage of the readily synthesized, substituted 1,3-dithietanes 3 , due to the inaccessibility of 2 from the latter. The successfully synthesized 1,3-dithietanes 5c,d are expected to provide 2 , the key precursor of 1 via 1,3-dihalogenation-dehalogenation.