STEREOCHEMISTRY-61. AMINO ACID-CATALYZED ENANTIOSELECTIVE DEHYDRATION OF CYCLIC β-KETOLS

Article abstract of DOI:10.1016/S0040-4020(01)87620-1

Optically active octalones result from dehydration of the corresponding racemic β-ketols catalyzed by (S)-phenylalanine or (S)-proline.According to the nature of the amino acid, opposite enantioselectivities were observed during the kinetic resolutions.Catalysis by proline leads to higher enantiomeric excesses and occurs with greater discrimination between different substrates.A mechanism involving an intramolecular hydrogen transfer mediated by the amino-acid carboxylate group is consistent with the observed selectivities.