合成路线1

This compound can be obtained by two related ways: 1) The reaction of L-lysine (I) with NaNO2 - H2SO4 in water gives 6-amino-2(S)-hydroxyhexanoic acid (II), which is protected with benzyl chloroformate as usual yielding the N-benzyloxycarbonyl compound (III). The condensation of (III) with L-proline benzyl ester (IV) by means of hydroxybenzotriazole (HBT) and dicyclohexylcarbodiimide (DCC) affords the acylated proline ester (V), which is esterified with 4-phenylbutylphosphonous acid (VI) by means of DCC and dimethylaminopyridine (DMAP), and oxidized with NaIO4 to give the protected phosphonic ester (VIII). Finally, this compound is debenzylated by hydrogenation of Pd/C in methanol. The phosphonous acid (VI) is obtained by reaction of 4-phenyl-1-butene (VII) with sodium hypophosphite by means of azobisisobutyronitrile (AIBN). 2) The condensation of acylated proline ester (V) with dibenzyl 4-phenylbutylphosphonate (IX) by means of PCl5, triethylamine and DMAP also gives the protected phosphonic ester (VIII). The dibenzyl phosphonate (IX) is obtained by condensation of 4-phenylbutyl chloride (X) with dibenzyl phosphite (XI) by means of NaH in DMF.