Boron trifluoride etherate → Allyl 4-[1-oxo-3-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-2-propynyl]benzoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

4.3 g (20 mmol) of 5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-ethynylnaphthalene and 20 ml of THF were introduced into a three-necked flask under a stream of nitrogen. 12.5 ml (20 mmol) of an n-butyllithium solution (1.6M in hexane) were added dropwise at −78° C. and the reaction mixture was stirred for 10 minutes. 2.7 ml of BF3—Et2O were then added at this same temperature and the reaction mixture was stirred for 30 minutes. A solution of 2.5 g (10 mmol) of allyl 4-(N,N′-dimethylcarbamoyl)benzoate in 10 ml of THF was added, while maintained at −78° C., to the solution and stirring was carried out for 1 hour. The reaction mixture was poured into an aqueous ammonium chloride solution and extraction was carried out with ethyl ether. The organic phase was separated by settling, dried over magnesium sulfate and evaporated. The residue obtained was purified by chromatography on a silica column eluted with a mixture of dichloromethane and hexane (10/90). After evaporation of the solvents, 4.2 g (52%) of the expected ester were recovered in the form of an oil.

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