STEREOSELECTIVE SYNTHESIS OF A PYRIDOXAMINE COENZYME-AMINO ACID CHIMERA - ASSEMBLY OF A POLYPEPTIDE INCORPORATING THE PYRIDOXAMINE MOIETY

The stereoselective synthesis of ),3-O-bis-tert-butoxycarbonylpyridoxa min-5-yl)prop acid (4) was accomplished from pyridoxamine dihydrochlor ide. A key step is the stereoselective alkylation of (-)pseudoephedrin e glycinamide with the pyridoxamine bromide 7. Amenability of the amin o acid derivative 4 to solid phase methodology was demonstrated by its incorporation into a synthetic hexapeptide. Critical to the orthogona l protection of the pyridoxamine moiety is the in situ acetylation of the C3-hydroxyl group during peptide assembly.