4-Vinyl-1-cyclohexene → 1-Butyl-1,2,3,4-tetrahydroanthracene-9,10-dione

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Reaction Steps

A solution of 78.0 g. (0.495 mole) naphthoquinone and 56.0 g. (0.52 mole) butadiene dimer in 200 ml. dioxane was heated at 90°-95° C. for 1 hour, and then at 80°-90° C. for 3 hours. The solution was then cooled and 2.0 g. 10% palladium-on-charcoal (Pd/C) catalyst added. The mixture was then hydrogenated at 42 psi until the theoretical amount of hydrogen was taken up. After removal of the catalyst by filtration and addition of 2 ml. DBN, a slow stream of air was blown through the solution for 6 hours. The solution was then poured into 2000 ml. water and the mixture extracted three times with 300 ml., 100 ml. portions of cyclohexane. The combined cyclohexane extracts were dried over anhydrous potassium carbonate, treated with Darco activated charcoal (Atlas Chemical Industries), and then filtered. After removal of the solvent by using a steam bath, 73.0 g. of crude product was obtained (59% yield). The product was purified by chromatography on acidic alumina using cyclohexane eluent. An analytical sample, after recrystallization from methanol, had m.p. 64°-65° C.

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