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(±)-ω-Halo-α-(chloroacetoxy)phosphonates were kinetically resolved by use of a protease (Chirazyme ® P-2). The esters recovered at levels of conversion between 56 and 72 % furnished (S)-alcohols of 99 % ee. These were converted via azides into the phosphonic acid analogues of L -lysine, L -proline, L -ornithine and L -pipecolic acid. (-)-Phosphaproline was transformed into crystalline ureas derived from (R)- and (S)-1-phenylethyl isocyanate. X-ray structure analyses revealed that the levorotary phosphaproline has the R configuration, contrary to earlier reports.