反应详情

In an argon atmosphere, 10 ml of anhydrous tetrahydrofuran were added to 570 mg (3.0 mmol) of purified copper iodide (CuI) and 318 mg (7.5 mmol) of lithium chloride (LiCl) dried at a reduced pressure and 130° C., and the resultant solution was stirred at room temperature for about 30 minutes. The resultant transparent solution was cooled to about -60° C., a solution obtained by dissolving 336 mg (1.511 mmol) of the compound (17) obtained in step h in 3.5 ml of tetrahydrofuran was added to the above transparent solution, and 0.81 ml (6 mmol) of chlorotrimethylsilane chloride immediate after distillation were added to the above solution. The resultant mixture was stirred for 10 minutes, and 1.5 ml (5.5 mmol) of distilled and purified n-Bu3SnH were added thereto in a small amount each time over 5 minutes. Thereafter, cooling was stopped, and the temperature of the reaction solution was raised to 0° C. at room temperature over about 30 minutes. 20 ml of a 10% aqueous potassium fluoride solution were added to this reaction solution, and the mixture was stirred. The produced precipitate was filtered. This filtrate was extracted with tetrahydrofuran and concentrated, 30 ml of a 10% aqueous potassium fluoride solution were added to the residue, and the solution was stirred for 15 minutes. 30 ml of ether were further added to the above solution, and the resultant solution was stirred for 15 minutes. The stirred solution was filtered, the filtrate was separated, and the water layer thereof was extracted with ether. The extracted solution was collected and sequentially washed with water and brine solution and was dried with anhydrous magnesium sulfate. Then, the crude product obtained by concentrating the extracted solution was purified by chromatography using silica gel (270-400 meshes, 10 g, developing solution of hexane: ethyl acetate at a mixing ratio of 98:2 to 96:4), thereby obtaining 265 mg of a compound (18) (yield:78%). The IR and NMR spectra of the resultant compound (18) coincided with the reported data [References: Y. Nishida, et al, Agric. Biol. Chem., 51, 635 (1987) (to be referred to as reference 1 hereinafter) and R. E. Dolitle, et al, J. Chem. Ecol., 6, 473 (1980) (to be referred to as reference 2 hereinafter)]. Other physical data were as follows.

1. customdried at a reduced pressure and 130° C.
2. temperatureThe resultant transparent solution was cooled to about -60° C.
3. customa solution obtained
4. distillationafter distillation
5. additionwere added to the above solution
6. stirringThe resultant mixture was stirred for 10 minutes
7. distillation1.5 ml (5.5 mmol) of distilled
8. custompurified n-Bu3SnH
9. additionwere added
10. waitin a small amount each time over 5 minutes
11. temperatureThereafter, cooling
12. temperaturethe temperature of the reaction solution was raised to 0° C. at room temperature over about 30 minutes
13. addition20 ml of a 10% aqueous potassium fluoride solution were added to this reaction solution
14. stirringthe mixture was stirred
15. filtrationThe produced precipitate was filtered
16. extractionThis filtrate was extracted with tetrahydrofuran
17. concentrationconcentrated
18. addition30 ml of a 10% aqueous potassium fluoride solution were added to the residue
19. stirringthe solution was stirred for 15 minutes
20. addition30 ml of ether were further added to the above solution
21. stirringthe resultant solution was stirred for 15 minutes
22. filtrationThe stirred solution was filtered
23. customthe filtrate was separated
24. extractionthe water layer thereof was extracted with ether
25. customThe extracted solution was collected
26. washsequentially washed with water and brine solution
27. dry with materialwas dried with anhydrous magnesium sulfate
28. customThen, the crude product obtained
29. concentrationby concentrating the extracted solution
30. customwas purified by chromatography