反应详情

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.

1. concentrationThe medium is then concentrated under reduced pressure
2. customthe residue obtained
3. washwashed with brine (2×50 mL)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe residue obtained
8. customis purified by chromatography on silica gel
9. washeluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc