Perfluoro-3,4-dimethylhexa-2,4-diene

However, side reactions due to rearrangements are often observed. Thus, defluorination of perfluoro(3,4-dimethylhex-3-ene) gives perfluoro(3,4-dimethylhexa-2,4-diene) and its cyclobutene isomer.119,120 The latter is formed by an eleetrocyclic reaction. 

An efficient synthesis of hexakis(trifluoromethyl)cyclopentadiene 1 has been described very recently. Thus, a mixture of 1,1,3,3,3-pentafluoropropene (2 eq.), perfluoro-3,4-dimethylhexa-2,4-diene (1 eq.) and dried cesium fluoride (4 eq.) in anhydrous acetonitrile was sealed in a Carius tube which was rotated, using a mechanical arm, at room temperature for 48 hours. This gave 1 in 74% yield. 

The reaction of perfluoro-3,4-dimethylhexa-2,4-diene with calcium hypochlorite leads to the formation of a diepoxide, rearranging at 200 °C into the corresponding derivative of 1,4-dioxane (96RCI703). 

Chambers RD, Gray WK, Mullins SJ, Kom SR (1997) Reactions involving fluoride ion. Part 42 Heterocyclic compounds from perfluoro-3,4-dimethylhexa-2,4-diene. J Chem Soc Perkin... 

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