We describe a new route for the synthesis of thieno [3, 4-b] thiophene, alkyl derivatives thereof, seleno [3, 4-b] thiophene, and thieno [3, 4-b] furan made from inexpensive starting materials, such as thiophene-2-carboxylic acid and furan-2-carboxylic acid. Such fused heterocycles are of great interest for low band gap organic semiconductors and applications including OLEDs, organic photovoltaic cells, and electrochromics.
![dihydroseleno[3,4-b]thiophene Structure](https://image.chemsrc.com/caspic/155/1221182-01-9.png)
![selenopheno[3,4-b]thiophene Structure](https://image.chemsrc.com/caspic/345/74070-00-1.png)
