Synthesis of enantiomerically pure 1-amino-2-phenylcycloalkanecarboxylic acids (cnPhe)

Constrained amino acids have become very important tools for modern drug discovery research. Phenylalanine is an ­appropriate residue for study, due to its participation in active site recognition. The series of 1-amino-2-phenylcycloalkanecarboxylic acids - cnPhe - constitutes an attractive family of constrained ­analogues of phenylalanine that can provide different orientations of the phenyl moiety. All stereoisomers of this series, from the ­cyclopropane to the cyclohexane members, are available in enantio­merically pure form.