Chiral environments for asymmetric hydrogenation of model didehydro‐amino acid residues
John S. Davies, Mark C. Eaton, M. N. IBRAHIM · Journal of Heterocyclic Chemistry · 1980
Abstract Dedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday Nmr and glc analysis of diastereoisomeric mixtures of dipeptides has been used to study the asymmetric hydrogenation of model benzoyldidehydro‐ and trifluoroacetyldidehydro‐dipeptide methyl esters. Chiral enhancement of one isomeric form appears to be independent of the N‐terminal acyl group, but is significantly influenced by the choice of amino‐acid in the C‐terminal position. C‐Terminal aromatic amino‐acids and their derivatives give the best chiral enhancement during hydrogenation of a neighbouring dehydroamino‐acid residue.