Acetic Acid → ethyl 3-oxotetrahydro-2H-thiopyran-2-carboxylate

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Reaction Steps

To a solution of 5 g (219 mmol) of sodium in 13 mL of anhydrous EtOH and 88 mL of ether are added dropwise, at 0° C. and under argon, 20.5 g (87.5 mmol) of ethyl 4-[(2-ethoxy-2-oxoethyl)sulfanyl]butanoate. After stirring for 18 hours at room temperature, the reaction mixture is poured into a mixture of AcOH (12 mL)/ice (70 g). The medium is then concentrated under reduced pressure, and the residue obtained is taken up in 100 mL of ether, washed with brine (2×50 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The residue obtained is purified by chromatography on silica gel, eluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc. 5.64 g of ethyl 3-oxotetrahydro-2H-thiopyrane-2-carboxylate are obtained in the form of a yellow oil.

Provenance & Evidence