反应详情

温度

0 °C

A solution containing crude 19 (48 g) in reagent grade MeOH (480 mL) was cooled to 0° C. Aqueous NaOH (1 M, 144 mL) was added in one portion. After 30 min, TLC analysis revealed complete consumption of starting material [TLC analysis, 3:2 hexane/EtOAc, Rf(19)=0.7; Rf(20)=0.8]. The reaction mixture was neutralized with 1 N HCl and the product was extracted with DCM. The DCM extracts were washed with water, brine, dried over anhydrous Na2SO4, filtered, and concentrated. The crude product was absorbed onto 200 mL of silica gel and chromatographed (80% to 65% hexane/EtOAc) to afford 31.7 g of 20 as a thick oil. 1H NMR (CDCl3, 300 MHz) δ8.11 (br s, 1H), 7.65-7.57 (m, 1H), 7.04 (m, 1H), 6.96 (s, 1H), 6.87 (t, J=2.8 Hz, 1H), 4.16-4.09 (m, 1H), 3.45-3.14 (m, 3H), 2.76-2.63 (m, 1H), 1.75 (br s, 4H), 1.58 (s, 9H) ppm.

1. customconsumption of starting material [TLC analysis, 3:2 hexane/EtOAc, Rf(19)=0.7; Rf(20)=0.8]
2. extractionthe product was extracted with DCM
3. washThe DCM extracts were washed with water, brine
4. dry with materialdried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude product was absorbed onto 200 mL of silica gel
8. customchromatographed (80% to 65% hexane/EtOAc)