The reaction between allylmagnesium bromide and imines 5a-l leads to the corresponding 4-substituted 4-N-benzylaminobut-1-enes 6a-l, which were oxidized in a regioselective manner to the alkenylnitrones 7a-l. The intramolecular 1, 3-dipolar cycloaddition of these nitrones gave 2-spiroannulated or 2-substituted 6-exo-phenyl-1-aza-7-oxabicyclo [2.2. 1] heptanes 8a-j. Reductive cleavage of the NO bond of the obtained bicycles afforded the diverse substituted 4-hydroxypiperidines 9a-h in good yields. This stereoselective approach