反应详情

Ethylmagnesium bromide (0.110 mL, 3.0 M in THF, 0.330 mmol) was added dropwise to a stirring solution of methyl 1-(naphthalen-1-ylsulfonyl)piperidine-4-carboxylate (0.100 g, 0.30 mmol) and methyltitanium triisopropoxide (0.300 mL, 1.0 M in THF, 0.300 mmol) in tetrahydrofuran (3 mL) at 0° C. The reaction mixture was allowed to warm to ambient temperature over 2 h then quenched with water (15 mL). The resulting flocculent solution was diluted with ethyl acetate (15 mL) and filtered through Celite. The filtrate was extracted with ethyl acetate (2×10 mL). The combined organic extracts were dried over anhydrous sodium sulfate and concentrated in vacuo. The resulting residue was purified by column chromatography on SiO2 eluted with hexanes/ethyl acetate (1:1) to yield 0.035 g (35%) of the title compound as a white foam. 1H NMR (400 MHz, Chloroform-d) δ, ppm: 0.36-0.41 (m, 2 H), 0.67-0.71 (m, 2H), 0.90-0.98 (m, 1 H), 1.72 (dd, J=13.89, 1.26 Hz, 2 H), 2.49 (td, J=12.51, 2.53 Hz, 2 H), 3.91-4.02 (m, 2 H), 7.54-7.60 (m, 3 H), 7.92 (d, J=8.34 Hz, 1 H), 8.06 (d, J=8.08 Hz, 1 H), 8.21 (d, J=7.33 Hz, 1 H), 8.76 (s, 1 H); ESI-MS: m/z 332.3 (M+H)+.

1. customthen quenched with water (15 mL)
2. additionThe resulting flocculent solution was diluted with ethyl acetate (15 mL)
3. filtrationfiltered through Celite
4. extractionThe filtrate was extracted with ethyl acetate (2×10 mL)
5. dry with materialThe combined organic extracts were dried over anhydrous sodium sulfate
6. concentrationconcentrated in vacuo
7. customThe resulting residue was purified by column chromatography on SiO2
8. washeluted with hexanes/ethyl acetate (1:1)