[CH:1]1([C@H:4]2[C@H:8]([OH:9])[CH2:7][C:6](=[O:10])[N:5]2[C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:3][CH2:2]1.[C:18]([Si:22](Cl)([CH3:24])[CH3:23])([CH3:21])([CH3:20])[CH3:19].N1C=CN=C1>CN(C=O)C>[Si:22]([O:9][C@@H:8]1[CH2:7][C:6](=[O:10])[N:5]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[C@H:4]1[CH:1]1[CH2:2][CH2:3]1)([C:18]([CH3:21])([CH3:20])[CH3:19])([CH3:24])[CH3:23](2S,3R)-tert-Butyl 2-cyclopropyl-3-hydroxy-5-oxopyrrolidine-1-carboxylate (16) (1.34 g, 5.55 mmol) was placed in a flame-dried flask under nitrogen. DMF (12 mL) was added and the mixture stirred until dissolved. tert-butylchlorodimethylsilane (1.06 g, 7.02 mmol) and imidazole (0.558 g, 8.19 mmol) were added and the reaction stirred for 16 hr at rt. DMF was removed in vacuo and EtOAc (100 mL) was added and the organics were washed with sat. NaHCO3 (100 mL), brine (100 mL), dried with sodium sulfate, and concentrated in vacuo. The resulting crude product was purified via column chromatography using EtOAc/hexane gradients to yield (2S,3R)-tert-butyl 3-(tert-butyldimethylsilyloxy)-2-cyclopropyl-5-oxopyrrolidine-1-carboxylate (17) (1.78 g, 90%) as a white solid.
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