Triethylamine → (2S,4EZ)-1(tert-butoxycarbonyl)-4-(methoxyimino)-2-pyrrolidinecarboxylic acid

Participants

Reaction Steps

A solution was made containing (2S)-1-(tert-butoxycarbonyl)-4-oxo-2-pyrrolidinecarboxylic acid (Intermediate 1, 5.0 g, 21 mmol) and O-methylhydroxylamine hydrochloride (2.7 g, 32.8 mmol) in chloroform (100 ml) containing triethylamine (5.5 g, 55 mmol). The reaction mixture was then stirred at ambient temperature overnight, prior to removal of solvent. The resultant crude reaction mixture was dissolved in ethyl acetate (150 ml) and washed rapidly with 1N HCl (40 ml). The acidic layer was then extracted with ethyl acetate (3×20 ml) and the combined organic layers washed with brine before drying over magnesiom sulfate, filtering and removal of solvent in vacuo. The desired product (5.3 g, 94%) was isolated as a pale yellow oil.

Provenance & Evidence