反应详情

温度

110 °C

To a flask were added cis-cyclohexane-1,4-dicarboxylic acid (20 g, 116 mmol), n-butyl formate (581 ml, 5066 mmol), Dowex 50W×2 resin (87 grams), and octane (484 ml). The reaction mixture was heated to 110° C. overnight and then cooled and filtered. The resin was washed with 300 mL 1:1 hexane:EtOAc. The filtrate was concentrated and then taken up in toluene and re-concentrated. The resulting residue was dissolved in dichloromethane (119 ml) and then thionyl chloride (11.51 ml, 158 mmol) was added. The reaction mixture was heated to 38° C. overnight and then concentrated. The residue was taken up in DCM and re-concentrated (3×) to remove residual HCl. The resulting residue was dissolved in 1,4-dioxane (413 ml) and degassed with Ar for 30 minutes. Palladium (II) acetate (0.696 g, 3.10 mmol) was added and the mixture was degassed for an additional 30 minutes. Dimethyl zinc (2 M in toluene, 31.0 ml, 62.0 mmol) was added. The system was placed under argon through 3 cycles of evacuation and argon flushing then reacted at 38° C. overnight. The reaction mixture was cooled and diluted with water. The resulting mixture was filtered through a CELITE plug and then the solid was washed with EtOAc. The filtrate was concentrated and purified by column chromatography on silica gel (0-30% ethyl acetate/hexanes) to afford butyl cis-4-acetylcyclohexanecarboxylate. 1H NMR (500 MHz, DMSO-d6) δ 4.07 (t, J=6.6 Hz, 2H), 2.54-2.48 (m, 1H), 2.44-2.38 (m, 1H), 2.13 (s, 3H), 2.01-1.93 (m, 2H), 1.81-1.57 (m, 9H), 1.41-1.32 (m, 2H), 0.92 (t, J=7.5 Hz, 3H).

1. temperaturecooled
2. filtrationfiltered
3. washThe resin was washed with 300 mL 1:1 hexane
4. concentrationThe filtrate was concentrated
5. concentrationre-concentrated
6. dissolutionThe resulting residue was dissolved in dichloromethane (119 ml)
7. temperatureThe reaction mixture was heated to 38° C. overnight
8. concentrationconcentrated
9. concentrationre-concentrated (3×)
10. customto remove residual HCl
11. dissolutionThe resulting residue was dissolved in 1,4-dioxane (413 ml)
12. customdegassed with Ar for 30 minutes
13. customthe mixture was degassed for an additional 30 minutes
14. customthen reacted at 38° C. overnight
15. temperatureThe reaction mixture was cooled
16. filtrationThe resulting mixture was filtered through a CELITE plug
17. washthe solid was washed with EtOAc
18. concentrationThe filtrate was concentrated
19. custompurified by column chromatography on silica gel (0-30% ethyl acetate/hexanes)