Water → N-((2S,3S,5S)-5-Amino-3-hydroxy-1,6-diphenylhexan-2-yl)-2-(2,6-dimethylphenoxy)acetamide

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Reaction Steps

(2S,3S,5S)-2-(2,6-Dimethylphenoxyacetyl)amino-3-hydroxy-5-(t-butyloxycarbonylamino)-1,6-diphenylhexane (175.1 g, 0.32 mol) and 500 ml CH2Cl2 were mixed with stirring. CF3CO2H (249 ml, 3.2 mol) was added and stirred 20–25 minutes, then the reaction mixture was poured into a separatory funnel containing 1000 ml of water and 200 ml of CH2Cl2. The resulting mixture was shaken carefully and the layers were separated. The organic layer was washed again with 500 ml of water, then 3×500 ml of NaHCO3 and finally 500 ml of brine. The organic solution was dried over MgSO4, filtered and concentrated to a golden oil that pulled into a foam 300 ml of diethyl ether was added to the crude product and shaken vigorously to dissolve. Within minutes solid began to crystallize and the mixture became thick. Enough diethyl ether was added to make the mixture stirrable and the mixture was stirred at room temperature for 1 hour. The solid was filtered and air dried to give the desired product as 115 g of white needles, 81% yield.

Provenance & Evidence