Dimethyl Sulfoxide → HCID 21717629, compound

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Reaction Steps

A solution of (5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)methyl-triphenyl-phosphonium bromide (6.25 g, 11.5 mmol) and NaH (10.5 mmol), coming from 0.42 g of a dispersion of 60% NaH in oil, in 35 ml of anhydrous DMSO is agitated under argon for 20 minutes, during which a solution of 4-cyanoacetophenone (1.45 g, 10.0 mmol) in 15 ml of DMSO is added. The solution is agitated for 6 hours at ambient temperature then poured over ice (150 g). This was then extracted with ether (125 ml, 3×50 ml). The raw product is then purified by three successive flash chromatographies on silica (1st eluent hexane:acetone=5:95, 2nd eluent hexane:acetone=4:96, 3rd eluent hexane:acetone=2.5:97.5) so as to separate the (E) and the (Z) 4-[1-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-2-propenyl]benzonitriles. In order to obtain the pure (Z) isomer (less polar than the (E)isomer), the different fractions are verified by HPLC. The (E)isomer crystallises in the fractions coming from the flash chromatography. It is filtered, washed with hexane and dried at the palette pump. Its purity is determined by HPLC analysis.

Provenance & Evidence