Evaluation of Zard trifluoromethylketone synthesis for the preparation of potential bifunctional fluorinated synthons

In the quest for potential bifunctional fluorinated synthons, we examined the behavior of chlorodifluoroacetic and hexafluoroglutaric anhydride in their reaction with acid chlorides in the presence of pyridine under the conditions of Zard trifluoromethylketone synthesis. Chlorodifluoroacetic anhydride led easily to the expected chlorodifluoromethyl ketones in the case of relatively non-encumbered primary acid chlorides. In the case of hexafluoroglutaric anhydride we observed the unexpected formation of α substituted hexafluorocyclohexane-1,3-dione derivatives among with the corresponding fluorinated 3-chloro-cyclohexenones.