Towards the catalytic formation of α,β-vinylesters and alkoxy substituted γ-lactones

A facile, one pot, high yield synthesis of α,β-vinylester (1–14) and alkoxy substituted γ-lactones (15–28) has been achieved by the photochemical reaction of terminal acetylene (ferrocenyl phenyl trimethylsillyl, hexyl and cyclohexyl) with alcohol (methanol, ethanol and isopropanol) and carbon monoxide in presence of iron pentacarbonyl as a catalyst. The selectivity of the compounds depends on the time of photolysis of the reaction as well as the solvent used. A stable reaction intermediate ferrole was isolated, and further photolysis with alcohols, resulted in the formation of α,β-vinylester. All the compounds were fully characterised by spectroscopic methods and the molecular structures of compounds 1, 16, 17 and 20 were established crystallographically.

Graphical abstractPhotolytic reaction of terminal acetylenes, alcohols and carbon monoxide, in presence of catalytic amount of iron pentacarbonyl, results in the formation of α,β-vinylesters and alkoxy derivatives of γ-lactones. Selectivity of the products depends on the time of photolysis and solvent used.Figure optionsDownload full-size imageDownload as PowerPoint slide