-ketoester oximes the alkoxycarbonyl group proved a similar (ethoxy) or even better (t-butoxy) trapping nucleophile, leading preferentially to the corresponding bromolactone oxime. - With 2,2-dimethyl-3-butene aldoxime, the corresponding 3-bromopyrroline N-oxide was formed, due to a formal, unusual N-endo cyclization to the chain terminus. This was exploited for a new access to six-membered nitrones from