CN1CCOCC1.[O:8]=[C:9]1[CH2:13][CH2:12][CH2:11][N:10]1[CH2:14][CH2:15][C:16]([OH:18])=O.[CH:19]1([Mg]Br)[CH2:23][CH2:22][CH2:21][CH2:20]1>C1COCC1.[Cu](I)I>[CH:19]1([C:16](=[O:18])[CH2:15][CH2:14][N:10]2[CH2:11][CH2:12][CH2:13][C:9]2=[O:8])[CH2:23][CH2:22][CH2:21][CH2:20]12-Chloro-4-6-dimethoxy-1,3,5-triazine (2.68 g, 15.2 mmol) and N-methylmorpholine (4.2 mL, 38.1 mmol) were added to a solution of 3-(2-Oxo-pyrrolidin-1-yl)-propionic acid (2 g, 12.7 mmol, from Step 1) in THF (35 mL). After 1 h the reaction mixture was filtered through a glass frit to remove a white precipitate. The filtrate was treated with copper iodide (2.4 g, 12.7 mmol), cooled to 0° C. and then cyclopentyl magnesium bromide (6.35 mL, 12.7 mmol, 2M in ether) was added. After 4 h the resulting black mixture was quenched with saturated NH4Cl and extracted with CH2Cl2. The organic layers were washed with 1N HCl, saturated NaHCO3, brine, dried over Na2SO4 and concentrated. The residue was purifed by silica gel chromatography (75% EtOAc in hexanes then 5% MeOH in CH2Cl2) to give the title compound as a yellow oil. (0.4 g, 15% yield). 1H NMR (CDCl3): δ 1.55-1.83 (br m, 8H), 1.99 (m, 3H), 2.35 (t, 2H, J=8.3 Hz), 2.74 (t, 2H, J=6.8 Hz), 3.41 (d, 2H, J=7.2 Hz), 3.53 (t, 2H, J=6.6 Hz).
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