(2S,4R)-tert-butyl 4-(benzyloxycarbonylamino)-2-(4-(4-fluorophenoxy)phenylcarbamoyl)pyrrolidine-1-carboxylate → benzyl (3R,5S)-5-(4-(4-fluorophenoxy)phenylcarbamoyl)pyrrolidin-3-ylcarbamate

Participants

Reaction Steps

Step (c) A flask was charged with (2S,4R)-tert-butyl 4-(benzyloxycarbonylamino)-2-(4-(4-fluorophenoxy)phenylcarbamoyl)pyrrolidine-1-carboxylate and hydrogen chloride (4N in dioxane, 20 mL). The reaction mixture was stirred at ambient temperature for 1 hour and then quenched with saturated sodium bicarbonate (aq., 100 mL). The mixture was extracted with ethyl acetate (30 mL) and the extract was washed with deionized water (30 mL) and then brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was triturated with ethyl acetate to provide benzyl (3R,5S)-5-(4-(4-fluorophenoxy)phenylcarbamoyl)pyrrolidin-3-ylcarbamate (1.20 g, 2.67 mmol, 30% yield over 4 steps) as an off-white solid.

Provenance & Evidence