Oxalic Acid → 2-(trimethylsilyl)ethyl (1R,2S)-2-((S)-3-benzyloxycarbonylamino-2-oxopyrrolidin-1-yl)-5-oxocyclohexylcarbamate

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Reaction Steps

To a solution of 2-(trimethylsilyl)ethyl (1R,2S,5R)-5-amino-2-((S)-3-benzyloxycarbonylamino-2-oxopyrrolidin-1-yl)cyclohexylcarbamate (1.03 g, 2.099 mmol) in methanol (10 ml) was added 3,5-di-tert-butyl-1,2-benzoquinone (0.555 g, 2.52 mmol). This mixture was stirred for 2 hr before THF (6 mL) and water (2 mL) were added along with oxalic acid to pH 4. This mixture was concentrated. The resulting residue was dissolved in ethyl acetate and washed with brine. The organic layer was dried (MgSO4), filtered, and concentrated. This was purified via flash chromatography to give 2-(trimethylsilyl)ethyl (1R,2S)-2-((S)-3-benzyloxycarbonylamino-2-oxopyrrolidin-1-yl)-5-oxocyclohexylcarbamate (0.550 g, 1.123 mmol, 53.5% yield). LC/MS found [M+H]+=491.3.

Provenance & Evidence