SYNTHESIS OF 3-SUBSTITUTED AND 4-SUBSTITUTED CYCLIC ALPHA-AMINO-ACIDS STRUCTURALLY RELATED TO ACPD

The preparation of 3-substituted cyclopentanones 12-16, 4-substituted cyclohexanones 23-28 and cycloheptanones 38-41 is described. Substituents in the cycloalkanones are carboxylate, phosphonate or tetrazole groups, separated from the ring by a 0, 1, 2, or 3 carbon atoms chain. These cycloalkanones have been transformed into alpha-amino acids 9-11 by hydrolysis of the corresponding hydantoin derivatives 21, 37 and 62, obtained under Bucherer-Bergs reaction conditions.