Hydrogen Peroxide → 2-[2-(Tert-butoxy)-2-oxoethyl]-5-cyclohexylpentanoic acid

Participants

Reaction Steps

A solution of tert-butyl 3-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl}-6-cyclohexylhexanoate (64.0 g, 139.9 mmol) in tetrahydrofuran:water (3:1, 800 ml) was cooled to 5° C. then treated sequentially with hydrogen peroxide (30%w/v water, 87 ml, 769 mmol) then lithium hydroxide hydrate (10.0 g, 238 mmol). The reaction was stirred for 1 hour then quenched by dropwise addition of an aqueous solution of sodium thiosulphate (500 ml) keeping the temperature below 20° C. The mixture was extracted with ethyl acetate (discarded) and the aqueous phase was acidifed to pH 2 with solid citric acid and extracted with ethyl acetate. The combined organic phases were washed with brine, dried over anhydrous sodium sulphate and the solvent removed under reduced pressure. The residue was purified by column chromatography on silica gel eluting with a gradient system of hexane: ethyl acetate (2:1) gradually changing to hexane: ethyl acetate (1:1) to afford the title compound (40.7 g)

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