Dimethylformamide → 1,2,3,4-tetrahydro-1,1,4,4,7-pentamethyl-6-[(E)-alpha-methylstyryl]naphthalene

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Reaction Steps

A solution of diethyl benzylphosphonate in 30 ml of dimethylformamide is added at room temperature to a suspension of 3.7 g of NaH (50% in mineral oil) in 50 ml of dimethylformamide. After stirring at room temperature for 15 minutes a solution of 12.6 g of 7-acetyl-1,1,4,4,6-pentamethyltetralin in 60 ml of dimethylformamide is added dropwise thereto in the course of 2 hours. The reaction mixture is stirred at room temperature overnight and subsequently heated to 60° for a further 1 hour. After cooling the mixture is poured on to ice, extracted with ether, dried and evaporated. After chromatography of the crude product (silica gel elution agent hexane) and crystallization from hexane there are obtained 3.9 g of 1,2,3,4-tetrahydro-1,1,4,4,7-pentamethyl-6-[(E)-α-methylstyryl]naphthalene in colourless crystals, melting point 75°-77°.

Provenance & Evidence