反应详情

A mixture of 2-benzoyloxymethyl-3-oxo-1,3-oxathiolane (example 3) (10.5 g), tetra-n-butylammonium acetate (17 g) in acetic anhydride (250 ml) was heated at 110° to 120° C. under argon for 14 hours and cooled to room temperature. Excess acetic anhydride was removed under reduced pressure. The residue was dissolved in methylene chloride (500 ml), washed first with saturated aqueous NaHCO3 (2×200 ml), then with brine solution (200 ml), dried over MgSO4, filtered and evaporated in vacuo. The residue was purified by chromatography on silica gel using hexane:ethyl acetate (8:1) as eluant to give 7.4 g (60% yield) of the desired product as a mixture of cis- and trans- isomers. A small quantity of each isomer was also isolated and characterized by 1H- and 13C-NMR.

1. temperaturewas heated at 110° to 120° C. under argon for 14 hours
2. customExcess acetic anhydride was removed under reduced pressure
3. dissolutionThe residue was dissolved in methylene chloride (500 ml)
4. washwashed first with saturated aqueous NaHCO3 (2×200 ml)
5. dry with materialwith brine solution (200 ml), dried over MgSO4
6. filtrationfiltered
7. customevaporated in vacuo
8. customThe residue was purified by chromatography on silica gel