反应详情

To a stirred solution of 6α-carboxyandrostane-3,17-dione (II-aq, Prepn. 17, 34 mg) in CH2Cl2 (1.5 mL) at 0° C., MeOH (8 μL), DMAP (1 mg) and EDAC (39.4 mg) were added. After stirring overnight at room temperature, H2O was added and the mixture was extracted with CH2Cl2 (2×). The combined organic extracts were washed with H2O, brine, dried over Na2SO4, filtered and evaporated to dryness. The residue was purified by flash chromatography (SiO2, n-hexane/EtOAc 60/40) to give the title compound II-as (25 mg, 70%). 1H-NMR (300 MHz, DMSO-d6, ppm from TMS): δ 3.59 (s, 3H), 2.53-0.75 (m, 21H), 1.02 (s, 3H), 0.79 (s, 3H).

1. extractionthe mixture was extracted with CH2Cl2 (2×)
2. washThe combined organic extracts were washed with H2O, brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. customevaporated to dryness
6. customThe residue was purified by flash chromatography (SiO2, n-hexane/EtOAc 60/40)