反应详情

温度

85 °C

To a sealable vial containing (1R,3aS,5aR,5bR,7aR,11aR,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl trifluoromethanesulfonate (0.25 g, 0.448 mmol) was added diethyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)cyclohex-3-ene-1,1-dicarboxylate (0.374 g, 0.531 mmol), sodium carbonate hydrate (0.167 g, 1.345 mmol), and palladium tetrakis (0.016 g, 0.013 mmol). The mixture was diluted with 1,4-dioxane (4 mL) and water (1 mL) then was flushed with nitrogen and was sealed and heated to 85° C. in an oil bath. After 5 h of heating, the mixture was cooled to rt, was diluted with water (20 mL), and was extracted with ethyl acetate (3×20 mL). The combined organic layers were washed with brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography using a 10-50% ethyl acetate in hexanes gradient. diethyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-ene-1,1-dicarboxylate, a white solid, was recovered as the minor isolate (0.032 g, 0.05 mmol, 11.3% yield). LCMS: m/e 634.6 (M+H)+, 2.10 min (method 1).

1. customthen was flushed with nitrogen
2. customwas sealed
3. temperatureAfter 5 h of heating
4. temperaturethe mixture was cooled to rt
5. additionwas diluted with water (20 mL)
6. extractionwas extracted with ethyl acetate (3×20 mL)
7. washThe combined organic layers were washed with brine
8. dry with materialdried over magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe residue was purified by flash chromatography
12. customdiethyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-ene-1,1-dicarboxylate, a white solid, was recovered as the
13. customminor isolate (0.032 g, 0.05 mmol, 11.3% yield)
14. customm/e 634.6 (M+H)+, 2.10 min (method 1)