Sulfuric Acid → trans-Ethyl 2-hydroxycyclohexanecarboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Ethyl cyclohexanone-2-carboxylate (85.0 g, 0.5 mole) was dissolved in ethanol (200 ml) and the solution cooled to 0° C. Sodium borohydride (13.2 g, 0.35 mole) suspended in ethanol (80 ml) was added in small portions whilst the temperature was maintained at below 0° C. After stirring for 2 hours at 0° C. the reaction mixture was made faintly acid by the addition of 50% sulphuric acid and filtered. The filtrate was concentrated in vacuo, taken up in ether and washed with sodium bicarbonate solution. The organic phase was dried over magnesium sulphate and evaporated in vacuo. The residue was chromatographed on silica-gel, eluting initially with 3:1 hexane/ethyl acetate followed by 2:1 hexane/ethyl acetate to give 21.5 g of cis- and 10.0 g of trans-ethyl 2-hydroxycyclohexanecarboxylate.

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