2-Hydroxymethylthieno[2,3-b]-thiophene

thieno[2,3-b]thiophene-2-carboxaldehyde ethylene glycol acetal

5-formylthieno[2,3-b]thiophene-2-sulfonamide

methyl [3-(2-dioxolanyl)-thiophene-2-ylthio]acetate

5-(1,3-dioxolan-2-yl)thieno[2,3-b]thiophene-2-sulfonyl chloride