반응 #172731

반응 방정식

4-methoxycarbonylphenylboronic acid

(1R,3aS,5aR,5bR,7aR,11aR,11bR,13bR)-benzyl 5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-9-(trifluoromethylsulfonyloxy)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate

2-propanol

sodium carbonate monohydrate

→

title compound

수율 68.4%

(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-benzyl 9-(4-(methoxycarbonyl)phenyl)-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]chrysene-3a-carboxylate

수율 68.4%

용매

dioxane

water

반응 조건

후처리

1. 1
   기타The flask was attached to a reflux condenser
2. 2
   기타flushed with N2
3. 3
   온도heated
4. 4
   온도to reflux overnight
5. 5
   workup.ADDITIONdiluted with water (75 mL)
6. 6
   추출The mixture was extracted with ethyl acetate (3×75 mL)
7. 7
   세척washed with brine (75 mL)
8. 8
   건조The combined organic layers were dried with MgSO4
9. 9
   여과filtered
10. 10
    농축concentrated under reduced pressure
11. 11
    기타purified by silica gel flash chromatography
12. 12
    workup.ADDITIONThe fractions containing the expected product
13. 13
    농축concentrated under reduced pressure

실험 절차

To a solution of (1R,3aS,5aR,5bR,7aR,11aR,11bR,13bR)-benzyl 5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-9-(trifluoromethylsulfonyloxy)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate (6.21 g, 9.18 mmol) in dioxane (25 mL) was added 2-propanol (25 mL) and water (15 mL) followed by sodium carbonate monohydrate (3.42 g, 27.5 mmol), 4-methoxycarbonylphenylboronic acid (2.478 g, 13.77 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.318 g, 0.275 mmol). The flask was attached to a reflux condenser, flushed with N2 and heated to reflux overnight. The mixture was then cooled to rt and diluted with water (75 mL). The mixture was extracted with ethyl acetate (3×75 mL) and washed with brine (75 mL). The combined organic layers were dried with MgSO4, filtered, and concentrated under reduced pressure. The residue was adsorbed to silica gel and purified by silica gel flash chromatography using a 0-20% ethyl acetate in hexanes gradient. The fractions containing the expected product were combined and concentrated under reduced pressure to give the title compound (4.16 g, 6.28 mmol, 68.4% yield) as a white foam. 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 7.92 (d, J=8.24 Hz, 2H), 7.40-7.29 (m, 5H), 7.19 (d, J=8.24 Hz, 2H), 5.28 (dd, J=6.10, 1.83 Hz, 1H), 5.19-5.07 (m, 2H), 4.73 (d, J=1.83 Hz, 1H), 4.60 (s, 1H), 3.90 (s, 3H), 3.04 (td, J=10.91, 4.73 Hz, 1H), 2.20-2.32 (m, 2H), 2.09 (dd, J=17.24, 6.26 Hz, 1H), 1.95-1.82 (m, 2H), 1.69 (s, 3H), 0.97 (s, 3H), 0.95 (s, 3H), 0.92 (s, 3H), 0.91 (s, 3H), 1.75-0.87 (m, 17H), 0.82 (s, 3H).

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