Diels-Alder reactions of trifluoromethyl dienes obtained from ene reactions of trifluoromethyl carbonyl compounds

The ene reactions of trifluoromethyl carbonyl compounds give products which may be dehydrated to trifluoromethyl dienes; the Diels Alder reaction of these have been investigated. The dienes from trifluoromethyl ketones hardly reacted, probably because the steric effect of the trifluoromethyl group prevents the diene from taking up a cisoid form. Dienes obtained from the ene reaction of trifluoroacetaldehyde have one substituent at a terminal position and react with dienophiles to give trifluoromethylated cyclohexene derivatives.