反应详情

A solution of ethyl 2-tert-butoxy-2-(1-hydroxy-3-methylnaphthalen-2-yl)acetate (1.24 g, 3.92 mmol) in CHCl3 (20 mL) was treated with solid NaHCO3 (843 mg, 9.80 mmol). Then a solution of Br2 (750 mg, 4.70 mmol) in CHCl3 (5.0 mL) was added dropwise over 2 min at 23° C. After 30 min, the reaction was treated with 10% Na2S2O3 solution (10 mL). After maximum decolorization was achieved, the reaction was diluted with H2O (10 mL) and extracted with DCM (3×10 mL). Combined organic phases were dried (Na2SO4), filtered, and concentrated. The residue was treated with DCM and wet-loaded onto a silica gel column and purified by flash chromatography (ethyl acetate/hexanes) giving the desired product (1.50 g, 97% yield). 1H NMR (400 MHz, CDCl3) δ 9.18 (s, 1H), 8.28 (d, J=8.6 Hz, 1H), 8.20 (d, J=8.6 Hz, 1H), 7.56 (dd, J=8.6, 8.6 Hz, 1H), 7.45 (dd, J=8.6, 8.6 Hz, 1H), 5.60 (s, 1H), 4.24-4.06 (m, 2H), 2.77 (s, 3H), 1.31 (s, 9H), 1.20 (t, J=7.0 Hz, 3H).

1. extractionextracted with DCM (3×10 mL)
2. dry with materialCombined organic phases were dried (Na2SO4)
3. filtrationfiltered
4. concentrationconcentrated
5. additionThe residue was treated with DCM and wet-loaded onto a silica gel column
6. custompurified by flash chromatography (ethyl acetate/hexanes)