[C:1]1([C@@H:7]2[CH2:11][NH:10][C:9](=[O:12])[CH2:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[H-].[Na+].Br[CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18]>O1CCOCC1>[CH2:20]([O:19][C:17]([CH2:16][N:10]1[CH2:11][C@@H:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[CH2:8][C:9]1=[O:12])=[O:18])[CH3:21]The solution of 4(R)-phenyl-2-pyrrolidinone (1) (345 mg, 2.14 mM) in 1,4-dioxane (30 ml) was added to the suspension of sodium hydride (56 mg, 2.35 mM) in 1,4-dioxane (30 ml). The mixture was heated at 80÷90° C. during 30 min and then cooled to room temperature. Ethyl bromoacetate (393 mg, 2.37 mM) was added and the reaction mixture was refluxed at 110÷120° C. for 6 hours. Obtained mixture was concentrated under reduced pressure. Residue was purified by column chromatography on silicagel with ethylacetate-hexane mixture 1:1, giving N-ethoxycarbonylmethyl-4(R)-phenyl-2-pyrrolidinone (3) (338 mg, 64%). [α]D20=+4.6° (c=3; MeOH). 1H NMR (CDCl3), δ: 1.28 (3H, t, CH2CH3); 2.59 (1H, d, d, 3-CH2); 2.87 (1H, d, d, 3-CH2); 3.54 (1H, t, 5-CH2); 3.64 (1H, quintet, 4-CH); 3.83 (1H, t, 5-CH2); 4.11 (2H, s, NCH2CO); 4.20 (2H, q, CH2CH3); 7.20-7.39 (5H, m, C6H5).
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