反应详情

温度

-20 °C

To 520 ml of a methylene chloride solution of 10.98 g of titanium tetraisopropoxide cooled to -70° C., 12 ml of a methylene chloride solution of 12.07 g of D-(-)-diethyl tartarate was added dropwise, and the resulting mixture was stirred for 20 minutes. Then, 25 ml of a methylene chloride solution of 12.9 g of p-chlorocinnamyl alcohol was added dropwise, and the resulting mixture was stirred for 20 minutes. Then, 42.0 ml of t-butyl hydroperoxide (3.67 mol/l methylene chloride solution) was added dropwise, and the resulting mixture was stirred at 70° C. for 1.5 hours, at -40° C. for 2 hours and at -20° C. for 1.5 hours, and then brought to -10° C. over 1 hour and stirred at the same temperature for 2 hours. After it was cooled again to -20° C., 150 ml of an aqueous solution of 38.5 g of iron sulfate hexahydrate and 15.4 g of citric acid monohydrate was added dropwise over 0.5 hour below 5° C. The mixture was stirred vigorously at 0° C. for 0.5 hour and filtered through celite. The filtrate was allowed to separate, and the aqueous layer was extracted again with methylene chloride. The organic layers were combined and washed with a saturated sodium hydrogen carbonate aqueous solution, water and a saturated saline solution. After the solvent was distilled off, the residue was dissolved in diethyl ether, and sodium sulfate and activated carbon were added, and the mixture was allowed to stand for 0.5 hour. The mixture was filtered through celite, and the ether solution thus obtained was cooled with ice. 172 ml of 1N sodium hydroxide aqueous solution was added, and then, the resulting mixture was stirred vigorously for 1 hour. After it was allowed to separate, the organic layer was washed with water (twice) and with a saturated saline solution, treated with activated carbon and filtered through celite. After the solvent was distilled off, the residue was purified by silica gel chromatography (eluent; methanol/chloroform=1/99) and crystallized from cyclohexane to obtain 6.35 g of the title compound as white crystals of [α]D25 +39.42° (chloroform, c 1.042).

1. stirringthe resulting mixture was stirred for 20 minutes
2. stirringthe resulting mixture was stirred at 70° C. for 1.5 hours, at -40° C. for 2 hours and at -20° C. for 1.5 hours
3. waitbrought to -10° C. over 1 hour
4. stirringstirred at the same temperature for 2 hours
5. stirringThe mixture was stirred vigorously at 0° C. for 0.5 hour
6. filtrationfiltered through celite
7. customto separate
8. extractionthe aqueous layer was extracted again with methylene chloride
9. washwashed with a saturated sodium hydrogen carbonate aqueous solution, water
10. distillationAfter the solvent was distilled off
11. dissolutionthe residue was dissolved in diethyl ether
12. additionsodium sulfate and activated carbon were added
13. waitto stand for 0.5 hour
14. filtrationThe mixture was filtered through celite
15. customthe ether solution thus obtained
16. temperaturewas cooled with ice
17. stirringthe resulting mixture was stirred vigorously for 1 hour
18. customto separate
19. washthe organic layer was washed with water (twice) and with a saturated saline solution
20. additiontreated with activated carbon
21. filtrationfiltered through celite
22. distillationAfter the solvent was distilled off
23. customthe residue was purified by silica gel chromatography (eluent; methanol/chloroform=1/99)
24. customcrystallized from cyclohexane