Treatment of triethyl phosphoacetate (I) with NaH and 4-bromobenzyl bromide (II) in DMF provides the 2-substituted triethyl phosphoacetate (III), which then undergoes reaction with formaldehyde and K2CO3 to afford acrylate derivative (IV). Michael condensation of (IV) with phosphinic acid (V) in N,O-bistrimethylsilylacetamide (BSA) yields intermediate (VI), which then undergoes Suzuki condensation in toluene with phenylboronic acid (VII) and NaHCO3 in MeOH catalyzed by Pd(PPh3)4 to give (VIII). Hydrolysis of ethyl ester (VIII) by means of NaOH in EtOH furnishes carboxylic acid (IX), which is then coupled to L-alanine (X) by means of BOP and DIEA or Et3N in DMF to yield methyl ester (XI). Compound (XI) is then hydrolyzed by treatment with NaOH or LiOH in EtOH and, finally, the Z-protecting group is removed with BBr3 in dichloromethane.