Hydrogen Peroxide → 5-(2,4-Dimethoxybenzyl)-4-oxo-5-azaspiro[2.4]heptane-7-carboxylic Acid

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Reaction Steps

To a solution of lithium hydroxide monohydrate (142 mg) in water (5 ml) was added 30 wt % aqueous solution of hydrogen peroxide (0.8 ml) at −5° C., and the mixture was stirred for 15 minutes. To this reaction mixture were sequentially added tetrahydrofuran (5 ml) and a solution of an optically active compound of 7-((R)-4-benzyl-2-oxooxazolidine-3-carbonyl)-5-(2,4-dimethoxybenzyl)-5-azaspiro[2.4]heptan-4-one (1.39 g) in tetrahydrofuran (10 ml), and the mixture was stirred for additional 1 hour. To this reaction mixture was added a solution of sodium hydrogen sulfite (815 mg) in water (5 ml), and the mixture was stirred at room temperature for 1 hour, and then extracted with ethyl acetate. This organic layer was washed with a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate only). To the resulting solid was added diisopropyl ether/ethyl acetate/n-hexane (10/1/5, 10 ml), and the mixture was stirred. A solid was collected from this suspension by filtration, and dried under reduced pressure to give the titled compound (372 mg).

Provenance & Evidence