2 DIFFERENT PATHWAYS OF STEREOINFORMATION TRANSFER - ASYMMETRIC SUBSTITUTIONS IN THE (-)-SPARTEINE MEDIATED REACTIONS OF LATERALLY LITHIATED N,N-DIISOPROPYL-O-ETHYLBENZAMIDE AND N-PIVALOYL-O-ETHYLANILINE

Highly enantioenriched substitution products can be obtained by the (- )-sparteine mediated lithiation-substitution reactions of the laterall y lithiated intermediates 3 . 1 and 14 . 1 derived from the amides 2 a nd 13. Either enantiomer of the products can be obtained with high ena ntioenrichment using (-)-sparteine as the ligand by appropriate choice of the protocol. The enantiodetermining step in both sequences occurs after deprotonation. Enantioenrichment in the sequence with 3 . 1 ari ses from a dynamic kinetic resolution, whereas enantioenrichment in th e sequence with 14 . 1 arises from a dynamic thermodynamic resolution.