joined by amides to olefines were prepared in situ from the related aldehydes with N-methylhydroxylamine. The nitrones added intramolecularly to the olefin, and the cycloadditions gave fused γ-lactams 6 stereoselectively. A stereocentre located in position α to the nitronic functionality 13 completely controls the stereochemical course of the intramolecular cycloadditions, which exclusively affords compound