Abstract The intramolecular cycloaddition of α-substituted N-alkenylnitrones 2 leads to the 7- oxa-1-azanorbornanes 6, 7, and 8 with a selectivity of ca. 80% in favor of the exo, exo- disubstituted compound 6. The latter can be reduced to give the all-cis-2, 6-disubstituted 4- hydroxypiperidines 4 which are key compounds for the synthesis of certain alkaloids as demonstrated by the synthesis of lasubine II.
