Hydrogen Peroxide → (2R)-3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 3-[3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionyl]-4(S)-isopropyl-oxazolidin-2-one (1.88 g, 4.72 mmol) in tetrahydrofuran (73 mL) and water (22 mL) cooled to 0° C. was treated with a 30% aqueous hydrogen peroxide solution (2.1 mL) and lithium hydroxide (394 mg, 9.4 mmol). The reaction was stirred at 0° C. for 1 h. At this time, the reaction was quenched with a saturated aqueous sodium sulfite solution (16 mL) followed by the addition of an aqueous solution of 0.5N sodium bicarbonate (50 mL). The tetrahydrofuran was then removed in vacuo. The residue was diluted with water (40 mL) and extracted with methylene chloride (3×20 mL). The aqueous layer was then acidified to pH=2 with a 5N aqueous hydrochloric acid solution and extracted with ethyl acetate (4×25 mL). The ethyl acetate layers were then dried over sodium sulfate, filtered, and concentrated in vacuo to afforded of 3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionic acid (928 mg, 70%) as a white solid: mp 75.1-78.3, C; [α]23589=−50.3° (c=0.100, chloroform); EI-HRMS m/e calcd for C14H16Cl2O2 (M) 286.0527, found 286.0535.

Provenance & Evidence