[CH2:1]=[C:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH:4]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[CH2:3]1.B.[O:22]1CCCC1.[OH-].[Na+].OO>O1CCCC1.O>[OH:22][CH2:1][CH:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C:11]([CH3:14])([CH3:12])[CH3:13])=[O:9])[CH:4]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[CH2:3]1
To solution of tert-butyl 4-methylene-2-phenylpiperidine-1-carboxylate (2.20 g, 8.04 mmol) in tetrahydrofuran (50 mL) at 0° C. was added borane-tetrahydrofuran complex (1M solution in tetrahydrofuran) (12.1 mL, 12.1 mmol) and the reaction mixture was stirred at 0° C. for 1 hour. The reaction mixture was allowed to warm to room temperature then stirred for an additional 2 hours. It was cooled to 0° C. and 2M aqueous sodium hydroxide (8.0 mL, 16.0 mmol) was added slowly followed by the slow addition of 30% aqueous hydrogen peroxide (5.5 mL, 48.4 mmol). The mixture was stirred for another hour then diluted with water (100 mL) and partitioned with ethyl acetate (250 mL). The organic layer was separated and washed with 2M aqueous sodium thiosulfate (100 mL), brine, dried over anhydrous sodium sulfate, filtered and concentrated. Column chromatography in silica gel (chloroform:methanol 9:1 to 4:1) provided tert-butyl 4-(hydroxymethyl)-2-phenylpiperidine-1-carboxylate (1.86 g, 79%). 1H NMR (400 MHz, CDCl3): 7.30 (m, 2H), 7.20 (m, 3H), 4.86 (dd, 1H), 4.04 (m, 1H), 3.62 (m, 0.5H), 3.44 (m, 3H), 3.24 (m, 1H), 2.12 (m, 0.5H), 1.93 (m, 1H), 1.64 (m, 2H), 1.42 (m, 1H), 1.26 (s, 9H). GC/MS (EI) for C17H25NO3: 235 (M-tBu+).
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