Synthesis of 3‑Benzo[b]thienyl 3‑Thienyl Ether via an Addition–Elimination Reaction and Its Transformation to an Oxygen-Fused Dithiophene Skeleton: Synthesis and Properties of Benzodithienofuran and Its π‑Extended Derivatives

The synthesis of 3-benzo­[b]­thienyl 3-thienyl ether and its dehydrogenative cyclization leading to benzodithienofuran (BDTF; [1]­benzo­thieno­[3,2-b]­thieno­[2,3-d]­furan) are described for the first time. Further transformation of BDTF to more π-extended BDTF derivatives and their fundamental physical properties are also studied.