A new strategy for the elaboration of pyrrolidine N-oxides using the reverse-Cope elimination

Abstract

Condensations of the unsaturated nitrones 13 with lithiated methyl phenyl sulfone provide excellent yields of the unsaturated hydroxylamines 14 as single stereoisomers, which undergo rapid reverse-Cope elimination at ambient temperature, assisted by the constraint of the acetonide ring, leading to the pyrrolidine N-oxides 15 as single enantiomers.