(2S)-1-(3-methylbutanoyl)pyrrolidine-2-carboxylic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a well stirred solution of L-proline (1.15 g; 0.01 mole) in 2N aq. NaOH (5 ml), 4N aq. NaOH (2.5 ml) and iso-valeryl chloride (1.4 ml; 0.012 mole) were added simultaneously dropwise maintaining the temperature near 0°-4° C. After 15 minutes, the mixture was acidified (pH 2-3) with 1N HCl and extracted with CHCL3. The combined organic extract was dried using MgSO4, and the solvent was removed. N-iso-valeryl-L-proline was obtained as an oil. Yield 0.85 g, Rf =0.66 (Silica gel, n-C4H9OH-AcOH-H2O, 5:1:2); [α]D20 -129.3° (c 0.6; CHCl3). maintaining the temperature near 0°-4° C extracted with CHCL3 The combined organic extract was dried the solvent was removed