反应详情

To a solution of 5-bromo-3,3-dimethyl-2,3-dihydro-benzofuran (2.03 g, 8.93 mmol) in dry THF (10 mL) at −78° C., under argon, was added dropwise n-BuLi (1.6 M in hexane, 13.4 mmol, 8.38 mL). The mixture was stirred for 5 minutes then isobutyraldehyde (1.22 mL, 8.38 mmol) was added and the mixture was slowly warmed up to room temperature and stirred overnight at room temperature. Aqueous ammonium chloride was added and the solution extracted with ethylacetate and the organic extract was dried (MgSO4), filtered and evaporated. The residue was purified on silica gel (0% to 20% ethyl acetate in hexane) to give 1.97 g of 1-(3,3-dimethyl-2,3-dihydro-benzofuran-5-yl)-2 -methyl-propan-1-o1(100%). 1H NMR (300 MHz; CDC13): δ0.77(d, J=6.6 Hz, 3H), 0.90 (d, J=6.6 Hz, 3H), 1.33 (s, 6H), 1.95 (m, 1H), 4.23 (s, 2H), 4.28 (d, J=7.2 Hz, 2H), 6.72 (d, J=8.4 Hz, 1H), 7.03 (dd, J=8.1 Hz and 1.8 Hz, 1H), 7.06 (d, J=1.5 Hz, 1H).

1. stirringstirred overnight at room temperature
2. extractionthe solution extracted with ethylacetate
3. extractionthe organic extract
4. dry with materialwas dried (MgSO4)
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified on silica gel (0% to 20% ethyl acetate in hexane)