Lithium hydroxide, monohydrate → L-Proline, N-(methoxycarbonyl)-L-valyl-5-methyl-, (5S)-

Participants

Reaction Steps

To an ice-cold stirred solution of ethyl (2S,5S)-1-[(2S)-2-(methoxycarbonylamino)-3-methyl-butanoyl]-5-methyl-pyrrolidine-2-carboxylate (5.6 g, 17.8 mmol) in ethanol (18 ml) is added a solution of lithium hydroxide monohydrate (17.8 mL of 1.7 M, 30.3 mmol). The reaction mixture is stirred for 5 hours at rt. The reaction mixture is concentrated, diluted with water, washed with ether. The aqueous solution is acidified with aq. 1N HCl, extracted with CH2Cl2. The combined extracts are washed with brine, dried (Na2SO4), concentrated to afford (2S,5S)-1-[(2S)-2-(methoxycarbonylamino)-3-methyl-butanoyl]-5-methyl-pyrrolidine-2-carboxylic acid (5 g, 94%) as a white solid.

Provenance & Evidence