Benzyl Bromide → 2-Benzyl-3,4,8,8a-tetrahydro-8a-methyl-1,6(2H,7H)-naphthalenedione

関与物質

反応条件

反応手順

A solution of 3,4,8,8a-tetrahydro-8a-methyl-1,6(2H,7H)-naphthalenedione (2.5 g, 0.014 mole) in dry tetrahydrofuran (20 ml) was added to lithium diisopropylamide [made from dry diisopropylamine (1.95 ml 0.014 mole) and n-butyl-lithium (12.0 ml of a 1.15 M solution in hexane, 0.014 mole)] at -65° C. under nitrogen. The solution was allowed to warm to 0° C. and a solution of benzyl bromide (2.39 g, 0.014 mole) in dry tetrahydrofuran (6 ml) was added. This was stirred at room temperature overnight, poured into water and extracted with diethyl ether (100 ml). The organic phase was washed with 1 N hydrochloric acid (50 ml) and water (50 ml), then dried (Na2SO4) and evaported to give a dark oil. This was chromatographed on silica gel using diethyl ether/petroleum ether (1:1) as eluant giving the title compound which was further purified by distillation b.p. 190° C./0.01 mm. The product was isolated as a mixture of isomers.

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