Use of 1,3-Dioxin-4-ones and Related Compounds in Synthesis. XXXVIII. Use of 1,3-Dioxin-4-ones Having a Fluorine or Trifluoromethyl Group at the 5-Position as .PI.2 Components in (2+2)-Photocycloaddition and Diels-Alder Reactions.
Fluorination of 5,6-unsubstituted 1,3-dioxin-4-ones by fluorine followed by treatment with triethylamine affords the title compounds, which can be converted into fluorinated derivatives of either formylacetic acid or of heterocyclic systems.