[CH2:1]([O:3][C:4](=[O:18])[CH:5]([C:11]([C:13]1[NH:14][CH:15]=[CH:16][CH:17]=1)=[O:12])[C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH3:2].C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[CH2:29](Br)[C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=1>COCCOC.C(OCC)(=O)C>[CH2:1]([O:3][C:4](=[O:18])[C:5]([CH2:29][C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=1)([C:11]([C:13]1[NH:14][CH:15]=[CH:16][CH:17]=1)=[O:12])[C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH3:2]2-(1H-Pyrrole-2-carbonyl)-malonic acid diethyl ester (0.79 mmol, 0.21 g) in DME (3 ml) was treated with lithium bis-trimethylsilylamide (0.79 mmol, 133 mg). The resulting solution was held at room temperature for 30 minutes, then treated with benzyl bromide (0.79 mmol, 0.10 ml). The resulting solution was held at room temperature overnight, then diluted with ethyl acetate (30 ml), and washed with saturated ammonium chloride (10 ml), followed by brine (20 ml). The organics were concentrated under reduced pressure and the residue was purified by silica gel chromatography to provide 0.23 g (84%) of 2-benzyl-2-(1H-pyrrole-2-carbonyl)-malonic acid diethyl ester. 1H NMR (CDCl3) δ10.01 (1H, s), 7.25-7.17 (4H, m), 7.14 (1H, dt, J=2.7, 1.3), 7.03-6.98 (1H, m), 6.86 (1H, ddd, J=3.8, 2.4, 1.3), 6.29-6.25 (1H, m), 4.22 (4H, q, J=7.1), 3.47 (2H, s), 3.39 (2H, s), 1.25 (6H, t, J=1.7).
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