Synthesis and characterization of amino protected peptides derived from amino-α- hydroxyiminophosphonates

Abstract Diisopropyl 2-amino-1-hydroxyiminoethylphosphonate ( 2a ), derived from glycine, and diisopropyl 4-am1no-1-hydroxyiminobutylphosphonate ( 2c ), derived from GABA, were reacted with Boc-L-Phe-OH by the mixed anhydride method to yield novel peptide analogs diisopropyl 2-(t-Boc-L-Phe)amino-1-hydroxyiminoethylphosphonate ( 3a ) and diisopropyl 4-(t-Boc-L-Phe)amino-1-hydroxyiminobutylphosphonate ( 3c ). Diisopropyl 3-amino-1-hydroxyiminopropylphosphonate ( 2b ), derived from β-Ala, and diisopropyl 2-amino-1-hydroxyiminopropylphosphonate ( 2d ), derived from DL-Ala, were reacted with Boc-DL-Ala-OH by the mixed anhydride method to give peptide analogs diisopropyl 3-(t-Boc-L-Ala)amino-1-hydroxyiminopropylphosphonate ( 4b ) and diisopropyl 2-(t-Boc-L-Ala)amino-1-hydroxyiminopropylphosphonate ( 4d ) respectively. 1 H, 31 P NMR and FAB Mass spectra of the peptide analogs are reported.