Hydrogen Peroxide → (2R)-2-[[4-methoxy-3-(3-methoxypropoxy)phenyl]methyl]-3-methylbutanoic acid

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Reaction Steps

0.434 liter of 30% hydrogen peroxide is slowly added to 300 g of 4(R)-benzyl-3-{2(S)-isopropyl-3-[4-methoxy-3-(3-methoxypropyloxy)-phenyl]-propionyl}-oxazolidin-2-one in 4.8 liters of tetrahydrofuran/water (3:1) at 0° C. After the addition of 31.2 g of lithium hydroxide, the mixture is stirred for 3 hours at 0°-20° C. 2.55 liters of 1.5M sodium sulfite solution are then added to the reaction mixture at 0°-15° C. and stirring is continued for a further 30 minutes. 1 liter of saturated sodium hydrogen carbonate solution is added and the tetrahydrofuran is evaporated off. The aqueous solution is washed repeatedly with dichloromethane and then acidified with 2N hydrochloric acid (pH 3.0). Extraction with dichloromethane and subsequent evaporation of the solvent yield the title compound: Rf (ethyl acetate/hexane=2:1)=0.30; m.p. 43.5°-44° C.

Provenance & Evidence