A PRACTICAL ROUTE TOWARDS α,β-UNSATURATED δ-LACTONES BASED ON A STRATEGY. SYNTHESIS OF (-)-ARGENTILACTONE

Article abstract of DOI:10.1016/S0040-4039(00)87834-X

The lithio derivative of methyl 3-phenylsulphonylorthopropionate 1 reacts with epoxides to give, after acidic work-up and treatment with p-toluenesulphonic acid, β-phenylsulphonyl δ-lactones 2.These are directly converted into the corresponding α,β-unsaturated δ-lactones 3 upon treatment with triethylamine or DBU.An application of this new method to the synthesis of (-)-argentilactone 4 is described.