(Trifluoromethyl)trimethylsilane → ethyl 6-(1-hydroxy-2,2,2-trifluoroethyl)-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate

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Reaction Steps

The aldehyde (Example 75, Step 1) (0.89 g, 3.0 mmol) was cooled to 0° C. and treated with a 0.5 M solution of trimethyl(trifluoromethyl)silane (8.4 mL, 4.2 mmol) and four drops of a 1.0M solution of tetrabutylammonium fluoride was added. The reaction was allowed to warm to room temperature and stirred for 21.1 hours. The reaction was quenched with 3 N HCl, extracted with ethyl acetate, washed with water, brine, dried over MgSO4, and concentrated in vacuo to give a brown oil (1.02 g). This oil was purified by flash chromatography over silica gel, eluting with 10% ethyl acetate/hexanes to afford a brown oil (0.77 g, 58%): 1H NMR (CDCl3/300 MHz) 7.72 (d, 1H, J=3.4 Hz), 7.34 (m, 2H), 6.99 (d, 1H, J=8.5 Hz), 5.71 (q, 1H, J=6.8 Hz), 4.83 (q, 1H, J=6.4 Hz), 4.33 (m, 2H), 1.35 (t, 3H, J=7.1 Hz), 0.11 (s, 9H). FABLRMS m/z 443 (M+H).

Provenance & Evidence