AbstractOxidation of the isomeric cyclopentadithiophenes by oxygen in the presence of potassiumt‐butoxide int‐butanol‐dimethyl sulfoxide (4 : 1), or Triton B in pyridine, caused a cleavage reaction to occur and gave the corresponding bithienylcarboxylic acids. In contrast, the dithienylmethanes gave the corresponding dithienyl ketones. The Michael reaction of 7H‐cyclopenta[1,2‐b: 4,3‐b′]dithiophene with acrylonitrile is a