N1C=CN=[CH:2]1.[Si:6](Cl)([C:9]([CH3:12])([CH3:11])[CH3:10])(C)C.OCC1N[C:20](=[O:22])[CH2:19]CC1.[CH:23]1[CH:28]=CC=C[CH:24]=1.[CH3:29][N:30]([CH:32]=[O:33])C>CCOC(C)=O>[C:9]([SiH2:6][O:22][C:20]([CH3:19])([CH3:2])[CH:29]1[NH:30][C:32](=[O:33])[CH2:28][CH2:23][CH2:24]1)([CH3:12])([CH3:11])[CH3:10]Imidazole (1.16 g, 17.0 mmol) and tert-butyldimethylsilyl chloride (1.18 g, 7.85 mmol) were added sequentially to a solution of racemic 6-hydroxymethyl-piperidin-2-one (prepared from racemic α-aminoadipic acid according to Huang, et al., Synth. Commun. 1989, 19, 3485–3496, 921 mg, 7.14 mmol) in DMF (10 mL) at 0° C. The reaction mixture was allowed to warm to rt and was stirred at rt for 17 h. Benzene and EtOAc (3:7, 200 mL) was added and the solution was washed with brine (3×50 mL). The organic phase was dried (Na2SO4), filtered and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (CH2Cl2→3% MeOH/CH2Cl2, gradient) afforded 1.53 g (88%) of 6-(tert-butyl-dimethyl-silanyloxymethyl)-piperidin-2-one as a white solid.
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