反应详情

A tetrahydrofuran solution of 3-(chloromagnesio)-2-(phenoxymethyl)-1-propene (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 (Desc.1) in THF (3 ml). The solution was stirred at room temperature for 1 hour, quenched by addition of saturated ammonium chloride solution (20 ml) and extracted with ethyl acetate (20 ml). The organic phase was washed (saturated brine), dried (MgSO4), evaporated to a small volume and purified by chromatography on silica gel eluting with hexane containing increasing proportions of ethyl acetate between 0% to 20%. Evaporation of the fractions gave (2S,3R)-1-tert-butoxycarbonyl-3-hydroxy-3-(2-methylene-3-phenoxypropyl)-2-phenylpiperidine. MS (ES+) m/z 424 (M+H), 324 (M+2H-tBuOCO--), 368 (M+2H-tBu). 1H NMR (360 MHz, CDCl3) δ 7.48 (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), 1.36 (9H, s).

1. customquenched by addition of saturated ammonium chloride solution (20 ml)
2. extractionextracted with ethyl acetate (20 ml)
3. washThe organic phase was washed (saturated brine)
4. dry with materialdried (MgSO4)
5. customevaporated to a small volume
6. custompurified by chromatography on silica gel eluting with hexane containing
7. temperatureincreasing proportions of ethyl acetate between 0% to 20%
8. customEvaporation of the fractions