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 ethyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)cyclohex-3-enecarboxylate (0.138 g, 0.493 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, diluted with water (20 mL), and extracted with ethyl acetate (3×20 mL). The 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 6-50% ethyl acetate in hexanes gradient and 40 g silica gel column. The fractions containing the expected product were combined and concentrated under reduced pressure to give ethyl 4-((1R,3 aS,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-enecarboxylate (0.119 g, 0.212 mmol, 47.3% yield) as an off-white solid. LCMS: m/e 562.6 (M+H)+, 2.13 min (method 1). 1H NMR (500 MHz, chloroform-d) δ=5.35 (br. s., 1H), 5.19 (d, J=6.1 Hz, 1H), 4.73 (d, J=1.9 Hz, 1H), 4.60 (s, 1H), 4.15 (q, J=7.1 Hz, 2H), 2.58-2.47 (m, 2H), 2.33-2.27 (m, 2H), 2.23-1.94 (m, 6H), 1.70 (s, 3H), 1.27 (t, 3H), 1.07 (s, 3H), 1.79-0.82 (m, 34H).

1. customthen was flushed with nitrogen
2. customwas sealed
3. temperatureAfter 5 h of heating
4. temperaturethe mixture was cooled to rt
5. additiondiluted with water (20 mL)
6. extractionextracted with ethyl acetate (3×20 mL)
7. washThe 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. additionThe fractions containing the expected product
13. concentrationconcentrated under reduced pressure