Phenacylideneaniline was formed by Et 3 N-catalyzed elimination reaction of the hydroxylamine obtained from silyl enol ether 5a and nitrosobenzene (6). By this method, one- pot procedure was possible for cycloaddition reactions of the related anils. From these reactions, it was revealed that 6 reacted efficiently with a silyl enol ether having a π-donating substituent.
