KPPh2 → HCID 131722243, compound

Participants

Reaction Steps

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.

Provenance & Evidence