Doubly diastercoselective 1.3-dipolar cycloadditions of chiral azomethine ylides to cinnamoyl moieties, attached to chiral auxiliaries, were investigated. The resulting trans-3.4-disubstituted pyrrolidines were obtained in diastereomeric ratios of up to 78:22. The influence on this ratio by the constitution of the chiral ylide,vas found to be rather small. (C) 2001 Elsevier Science Ltd. All rights reserved.