Asymmetric synthesis of a,b-substituted b-aminoalkanamides and stereochemical determination

Highly enantiomerically enriched beta-aminoalkanamides 12 and beta-phenylaminoalkanamides 13 have been prepared by the addition reaction of alpha-lithiated 2-alkyl-2-oxazolines 9-Li, derived from optically active oxazolines 9, to N-cumyl nitrones 2. The relative stereochemistry of alkanamides 5 and 6 has been established by 1D-NOESY experiments carried out on the related pyrimidinones 7, whereas the absolute configuration of alkanamides 12 and 13 has been confirmed by an X-ray analysis. (C) 2007 Elsevier Ltd. All rights reserved.