Diels–Alder reactions of polyfluorocyclohexa-1,3-dienes. Part 7. Reactions of perfluorotricyclo[6.2.2.0]dodeca-2,6,9-triene

Abstract

The synthesis of perfluorotricyclo[6.2.2.0]dodeca-2,6,9-triene (5)via dehydrofluorination of the Diels–Alder adduct (3) of penfluorocyclohexa-1,3-diene and 1H,2H-octafluorocyclohexene has been reinvestigated, and the overall yield improved. Dehydrofluorination of the adduct (3) in a flow system over sodium fluoride pellets is complicated by the 1,2-elimination of fluorine from the triene (5) to give perfluoro-1,4-dihydro-1,4-ethanonaph-thalene (6). The diene moiety of the triene (5) is reactive in Diels–Alder additions with alkenes and alkynes. The stereoselectivity of such additions is not consistent with the existence of a strong secondary orbital interaction with the neighbouring non-conjugated double bond.