Studies on organic fluorine compounds. Part 26. Diels–Alder reaction of hexakis(trifluoromethyl)bicyclo[2.2.0]hexa-2,5-diene

Abstract

Hexakis(trifluoromethyl)bicyclo[2.2.0]hexa-2, 5-diene (1). which had been reported to be unreactive with dienes, was heated with dienes at 140° to give Diels–Alder adducts in good yields. The temperature must be strictly maintained, since starting materials were recovered at lower temperature, and isomerization of (1) occurred at higher temperature. Reaction of (1) with cyclohexa-1, 3-diene gave benzene and the 3, 4-dihydro isomer of (1) probably through an ene reaction.