methyl (2S)-2-benzamido-3-phenylpropanoate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of dimethyl methylphosphonate (3.06 mL, 28.27 mmol, 8.0 eq) in anhydrous THF (30 mL) was cooled to −78° C. and 2.5 N n-BuLi (2.66 mL, 28.60 mmol, 8.0 eq) was added dropwise. After addition, the solution was stirred at −78° C. for 30 min and then a solution of compound 1 (1.00 g, 3.53 mmol, 1.0 eq) in anhydrous THF (20 mL) was added slowly. The resulting mixture was stirred at −78° C. for 1 h and then at ambient temperature for 1 h. The solution was acidified with 10% AcOH (20 mL), extracted with EtOAc (3×50 mL). The extract was washed with 10% NaHCO3, brine, dried over anhydrous MgSO4 and evaporation of the solvent gave a crude residue, which was subjected to column chromatography on silica gel elution with 100% EtOAc afforded dimethyl [(3S)-3-[(N-benzoyl)amino]-2-oxo-4-phenyl-butyl]phosphonate 2 as a pale yellow oil (0.876 g, 66%): Rf 0.34 (EtOAc); 1H NMR (300 MHz, CDCl3) δH 3.10 (2H, m, —CH2Ph), 3.34 (2H, m, —CH2—), 3.69 and 3.73 (6H, 2xs, 2xOMe), 5.10 (1H, m, —CH—) and 7.18-7.82 (10H, m, Ar—H). After addition The resulting mixture was stirred at −78° C. for 1 h at ambient temperature for 1 h extracted with EtOAc (3×50 mL) The extract was washed with 10% NaHCO3, brine dried over anhydrous MgSO4 and evaporation of the solvent gave a crude residue, which was subjected to column chromatography on silica gel elution with 100% EtOAc

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of dimethyl methylphosphonate (3.06 mL, 28.27 mmol, 8.0 eq) in anhydrous THF (30 mL) was cooled to −78° C. and 2.5 N n-BuLi (2.66 mL, 28.60 mmol, 8.0 eq) was added dropwise. After addition, the solution was stirred at −78° C. for 30 min and then a solution of compound 1 (1.00 g, 3.53 mmol, 1.0 eq) in anhydrous THF (20 mL) was added slowly. The resulting mixture was stirred at −78° C. for 1 h and then at ambient temperature for 1 h. The solution was acidified with 10% AcOH (20 mL), extracted with EtOAc (3×50 mL). The extract was washed with 10% NaHCO3, brine, dried over anhydrous MgSO4 and evaporation of the solvent gave a crude residue, which was subjected to column chromatography on silica gel elution with 100% EtOAc afforded dimethyl [(3S)-3-[(N-benzoyl)amino]-2-oxo-4-phenyl-butyl]phosphonate 2 as a pale yellow oil (0.876 g, 66%): Rf 0.34 (EtOAc); 1H NMR (300 MHz, CDCl3) δH 3.10 (2H, m, —CH2Ph), 3.34 (2H, m, —CH2—), 3.69 and 3.73 (6H, 2xs, 2xOMe), 5.10 (1H, m, —CH—) and 7.18-7.82 (10H, m, Ar—H). After addition The resulting mixture was stirred at −78° C. for 1 h at ambient temperature for 1 h extracted with EtOAc (3×50 mL) The extract was washed with 10% NaHCO3, brine dried over anhydrous MgSO4 and evaporation of the solvent gave a crude residue, which was subjected to column chromatography on silica gel elution with 100% EtOAc