Pentachloropentadienic acid was isolated, apart from the expected 5,5-dimetoxytetrachlorocyclopentadiene, in the reaction of hexachlorocyclopentadiene with potassium hydroxide in methanol. The structure of this minor product was established by X-ray crystallography. The plausible mechanism of its formation is discussed.

中文翻译：

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(2Z)-2,3,4,5,5-五氯五-2,4-二烯酸作为从六氯环戊二烯合成 5,5-二甲氧基四氯环戊二烯的次要产物

在六氯环戊二烯与氢氧化钾在甲醇中的反应中，除了预期的 5,5-二甲氧基四氯环戊二烯外，还分离出五氯戊二烯酸。这种次要产物的结构是通过 X 射线晶体学确定的。讨论了其形成的合理机制。