反应详情

To a −78° C. solution of 2-bromo-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (1.34 g, 5.0 mmol) in 6.9 mL of THF was added n-butyllithium (1.6 M, 3.13 mL, 5.0 mmol). After ten minutes, the solution was added via cannula to a B78° C. solution of diethyldichlorosilane (0.61 mL, 5.0 mmol) and THF (4.4 mL) and stirring continued for 1 hour. In a second flask containing 4-bromobenzyl tert-butyldiphenylsilyl ether (Compound 1, 3.19 g, 7.5 mmol) and THF (2 mL) at −78° C. was added n-butyllithium (1.6 M, 4.69 mL, 7.5 mmol). After ten minutes, the contents of the second flask were added via canula to the first flask. After 30 minutes at −78° C., the reaction was quenched by the addition of 5 mL of saturated aqueous NH4Cl. The solution was poured into a separatory funnel containing water and hexane. The layers were separated and the aqueous layer was extracted 3 times with hexane. The combined organic layers were washed once with brine, and dried over magnesium sulfate, and the solvents were removed under reduced pressure. The residue was dissolved in 20 mL of THF and treated with 3.2 g of tetrabutylammonium flouride (Tbaf) adsorbed onto silica gel (1-1.6 mmol flouride per gram). The suspension was stirred for 5 hours at room temperature and then the silica gel was washed with ether, and the separated ether extracts were dried over magnesium sulfate. The filtered solvents were removed under reduced pressure and the residue purified by silica gel chromatography (9:1, hexane:ethyl acetate) to give the title compound.

1. waitAfter ten minutes
2. additionthe solution was added via cannula to a B78° C
3. waitAfter ten minutes
4. additionthe contents of the second flask were added via canula to the first flask
5. waitAfter 30 minutes at −78° C.
6. customthe reaction was quenched by the addition of 5 mL of saturated aqueous NH4Cl
7. additionThe solution was poured into a separatory funnel
8. additioncontaining water and hexane
9. customThe layers were separated
10. extractionthe aqueous layer was extracted 3 times with hexane
11. washThe combined organic layers were washed once with brine
12. dry with materialdried over magnesium sulfate
13. customthe solvents were removed under reduced pressure
14. dissolutionThe residue was dissolved in 20 mL of THF
15. additiontreated with 3.2 g of tetrabutylammonium flouride (Tbaf)
16. washthe silica gel was washed with ether
17. dry with materialthe separated ether extracts were dried over magnesium sulfate
18. customThe filtered solvents were removed under reduced pressure
19. customthe residue purified by silica gel chromatography (9:1, hexane:ethyl acetate)