Ethyl 2-thiopheneglyoxylate → Ethyl alpha-cyclohexyl-alpha-hydroxythiophen-2-acetate

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Reaction Steps

To a stirred, cooled (0° C.) solution of ethyl thiophene-2-glyoxylate (125.6 g, 0.683 mol) in diethyl ether (2 litres) is added dropwise 2M cyclohexyl magnesium chloride in ether (400 ml, 0.8 mol) over 1 hour. After stirring at room temperature for 2 hours, the reaction is quenched by addition of saturated ammonium chloride solution (1 litre of a 270 g/l solution) and water (1 litre) ensuring the temperature does not rise above 20° C. The organic portion is separated and washed with brine (1 litre), dried over magnesium sulphate and concentrated in vacuo, to yield the titled compound as an orange oil which is used in the next step without further purification.

Provenance & Evidence