methyl (2S)-2-[(2-methylpropan-2-yl)oxycarbonylamino]-4-phenylbutanoate

Conditions: temp:-80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2.93 g of N-BOC homo phenylalanine methyl ester (10 mmol) are dissolved in 25 ml of absolute toluene under nitrogen and the solution is cooled to -80° C. 20 ml of -20% strength DIBA in toluene are added dropwise and the temperature maintained. Since the reaction was not complete after 1.5 h a further 3 ml of 20% strength DIBA were added. the temperature maintained a further 3 ml of 20% strength DIBA were added