Synthesis of tricarbonyl(vinylallene)iron(0) complexes from tricarbonyl(vinylketene)iron(0) complexes and their oxidation to 5,5-disubstituted furan-2(5H)-ones

Abstract

Addition of phosphonoacetate anions to tricarbonyl(vinylketene)iron(0) complexes gave tricarbonyl(vinylallene)iron(0) complexes. Stereoselectivity as high as 98 : 2 was observed and the relative stereochemistry of the major stereoisomers was elucidated by X-ray crystal structure analysis of the major isomer of [Fe^o{PhCHCHC(Me)CCHCO₂Bu^t}(CO)₃]9d, the product obtained from the reaction between [Fe^o{PhCHCHC(Me)CO}(CO)₃]7a and the anion of (EtO)₂ P(O)CH₂CO₂Bu^t8b. Reaction of the major isomers of the tricarbonyl(vinylallene)iron(0) complexes with FeCl₃ gave 5,5-disubstituted furan-2(5H)-ones.