Ammonium Chloride → (2S,3R)-1-tert-Butoxycarbonyl-3-hydroxy-3-(2-methylene-3-phenoxypropyl)-2-phenylpiperidine

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Reaction Steps

A solution of 3-(chloromagnesio)-2-(phenoxymethyl)-1-propene in THF (0.91 M, 3 ml) (Louw et. al., Tetrahedron, 48, 6087-6104, 1992, prepared from 2.74 mmol of 3-chloro-2-(phenoxymethyl)-1-propene) was slowly added to a solution of (2S)-1-tert-butoxycarbonyl-2-phenylpiperidin-3-one (Preparation 1) in THF (3 ml). The mixture was stirred at room temperature for 1 hours, then saturated aqueous ammonium chloride (20 ml) was added and the mixture was extracted with ethyl acetate (20 ml). The organic phase was washed with brine, dried MgSO4) and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with hexane/ethyl acetate (100:0 increasing to 80:20) to give the title compound. 1H NMR (360 MHz, CDCl3)δ7.48 (2H, d, J=6.9 Hz), 7.35-7.2 (6H, m), 6.9-6.88 (3H, m), 5.4 (1H, s), 5.15 (2H, d, J=13.7 Hz), 4.61 (2H, s), 4.11 (2H, m), 3.17 (1H, m), 2.66 and 2.59 (2H, AB d, J=14.0 Hz), 1.95 (2H, m), 1.79 (2H, m), and 1.36 (9H, s). m/z (ES+) 424 (M+1).

Provenance & Evidence