methyl 4-hydroxy-2-[(2-methylpropan-2-yl)oxycarbonylamino]butanoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: The ester was dissolved in 20 ml toluene at room temperature with PPh3 (0.94 g, 3.6 mmol), then added N-(4-chlorophenyl)-N-[(2S,4R)-1-(4-hydroxybenzoyl)-2-methyl-1,2,3,4-tetrahydroquinolin-4-yl]acetamide (0.31 g, 0.71 mmol) and stirred for 5 min. DEAD (0.626 g, 3.6 mmol) was added and the reaction was stirred for 18 h at room temperature. The reaction was concentrated and purified by silica gel chromatography (45% CH2Cl2/55% EtOAc) to afford crude methyl 4-(4-{[(2S,4R)-4-[acetyl(4-chlorophenyl)amino]-2-methyl-3,4-dihydroquinolin-1(2H)-yl]carbonyl}phenoxy)-2-[(tert-butoxycarbonyl)amino]butanoate (0.47 g). The reaction was concentrated purified by silica gel chromatography (45% CH2Cl2/55% EtOAc)

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

Procedure: 2-tert-Butoxycarbonylamino-4-hydroxy-butyric acid (0.79 g, 3.6 mmol) was dissolved in 15 ml methanol at room temperature and (trimethylsilyl)diazomethane (2M solution in hexane) was added till solution become yellow. The mixture was concentrated down to afford crude 2-tert-butoxycarbonylamino-4-hydroxy-butyric acid methyl ester. The mixture was concentrated down