di-tert-butyl 2-(1λ4-thieno[3,2-b]thiophen-1-ylidene)malonate

2-thiophen-3-ylsulfanylacetic acid

2,3-dihydro-3-oxothieno[3,2-b]thiophen

2-trimethylsilylthieno[3,2-b]thiophen