反应详情

In a 250 ml Schlenk tube fitted with a septum, 1.58 g (6.31 mmol) of 12 were dissolved in 50 ml of THF, deprotonated at 0° C. by addition of 2.75 ml of n-BuLi solution and stirred further for half an hour. Via a capillary hose, one equivalent of a lithium dibenzophospholide solution was added dropwise at 0° C. over a period of half an hour. The yellow-orange reaction mixture was stirred for another 2 hours at this temperature and subsequently evaporated to about 30 ml in an oil pump vacuum. At room temperature, the reaction solution was then added to 3.5 equivalents of a potassium diphenylphosphide solution over a period of 1 minute and the mixture was stirred for 16 hours at room temperature. The solvent was subsequently substantially removed in an oil pump vacuum and the residue was taken up in 50 ml of diethyl ether. Hydrolysis was carried out by adding 20 ml of water and stirring for 10 minutes. The organic phase was separated off and the aqueous phase was extracted twice with 30 ml of diethyl ether. The combined ether phases were washed with sodium chloride solution until neutral and dried over sodium sulfate. The solvent was removed in an oil pump vacuum, the residue was dissolved in methylene chloride and absorbed on kieselguhr. This was followed by flash chromatography on silica gel (20*4 cm; eluant: PE/diethyl ether in a ratio of 9.75:0.25; RF =0.31). This gave 0.7 g (22%) of 5d as a colorless, viscous oil.

1. stirringThe yellow-orange reaction mixture was stirred for another 2 hours at this temperature
2. customsubsequently evaporated to about 30 ml in an oil pump vacuum
3. stirringthe mixture was stirred for 16 hours at room temperature
4. customThe solvent was subsequently substantially removed in an oil pump vacuum
5. customHydrolysis
6. stirringstirring for 10 minutes
7. customThe organic phase was separated off
8. extractionthe aqueous phase was extracted twice with 30 ml of diethyl ether
9. washThe combined ether phases were washed with sodium chloride solution until neutral and
10. dry with materialdried over sodium sulfate
11. customThe solvent was removed in an oil pump vacuum
12. dissolutionthe residue was dissolved in methylene chloride
13. customabsorbed on kieselguhr