Pyridine → 1-Cyclohexene-1-carboxylic acid, 4-methyl-6-oxo-, ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A suspension of phenylselenium chloride (27.29 g) in dichloromethane (250 mL) was stirred at 0° C. and treated dropwise with pyridine (11.81 g). The resulting mixture was stirred for 30 min, and then treated with a solution of racemic ethyl 4-methyl-2-oxocyclohexanecarboxylate (25 g) in dichloromethane (20 mL) in one portion. The color changed from brown to yellow, and the mixture was stirred at 0° C. for 15 min. After this time, the mixture was washed twice with 1 M aqueous HCl. The organic layer was cooled to 0° C. and then treated with 30% aqueous hydrogen peroxide (10.5 mL). After stirring for 10 min, an additional 30% aqueous hydrogen peroxide (10.5 mL) was added, followed by another an additional 30% aqueous hydrogen peroxide (10.5 mL) after 20 min. The resulting solution was stirred for 15 min and then treated with water (100 mL). The aqueous and organic layers were separated and the aqueous layer was extracted twice more with dichloromethane. The combined organic layers were washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate and concentrated under vacuum to provide racemic ethyl 4-methyl-6-oxocyclohex-1-enecarboxylate (26 g).

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