1,4-Cyclohexanedicarboxylic acid, 2,5-dioxo-, 1,4-diethyl ester → rel-(1R,4S)-2,5-Bis(methylene)-1,4-cyclohexanediol

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Reaction Steps

A warm solution of dry, recrystallized diethyl 1,4-cyclohexanedione-2,5-dicarboxylate (30.75 g, 120 mmol) in 350 ml anhydrous tetrahydrofuran (THF) was added to a refluxing solution of 1.0 M LAH in THF (600 mL) over a 2 hour period. After an additional 1.5 hours at reflux and subsequent cooling, a saturated solution of aqueous Rochelles's salt (app. 73 mL) was added dropwise to the reaction mixture. The tartrate complex was filtered, washed with THF and the filtrate was concentrated to a paste. The paste was recrystallized from hot ethyl acetate; yield 4.39 g (31.3 mmol, 26.1%). A second recrystallization yielded 3.81 g (27.2 mmol, 22.6%).

Provenance & Evidence