An unusual fluoroketene reaction product

The reaction of fluoroketene generated by the addition of triethylamine to a solution of 1,3-cyclohexadiene and fluoroacetyl chloride gave the expected [2 + 2] cycloaddition product. However, when the addition was reversed, an unexpected adduct arising from the reaction of four equivalents of fluoroketene with one equivalent of 1,3-cyclohexadiene was produced.