Hydrogen Peroxide → (S)-3-(tert-butoxycarbonyl(cyclopropylmethyl)amino)-2-(4-chlorophenyl)propanoic acid

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Reaction Steps

LiOH (1.41 g, 33.5 mmol) was added to a flask containing THF (360 mL) and H2O (120 mL), which was stirred until dissolved. At this point, the reaction was cooled to 0° C. with ice, and hydrogen peroxide (35 wt. %, 6.52 g) was added. This solution was stirred for 10 minutes, at which point tert-butyl (S)-3-((R)-4-benzyl-2-oxooxazolidin-3-yl)-2-(4-chlorophenyl)-3-oxopropyl(cyclopropylmethyl)carbamate (8.6 g, 16.8 mmol) was added as a solution in THF (20 mL). The reaction was stirred overnight with warming. The reaction was quenched by the addition of 10% aqueous Na2SO3 (1 mL) and saturated aqueous NaHCO3 (1 mL) and stirred for 10 minutes. The reaction was concentrated to remove THF and the aqueous layer extracted with ether (3×). The aqueous layer was diluted with EtOAc and acidified with 1N HCl. The organic layer was removed, and the aqueous layer was extracted with EtOAc (2×). The combined organics were dried with MgSO4 and concentrated to give the crude product, (S)-3-(tert-butoxycarbonyl(cyclopropylmethyl)amino)-2-(4-chlorophenyl)propanoic acid as a clear oil (LCMS (APCI+) [M−Boc+H]+ 254.1; Rt: 3.03 min).

Provenance & Evidence