Direct preparation of lanthanoid ester homoenolates from 3-halo esters and lanthanoid metals: their homo-Reformatskii type reaction with carbonyl compounds
Samariumdi-iodide is an efficient reagent for the reductivecoupling of ketones or aldehydes and electron-deficientalkenes, whereby γ-lactones can be prepared in good yields from ethyl acrylate.
γ-Lactones were easily prepared from the directreaction of methyl β-bromopropionate with ketones mediated by lanthanoidmetals; a lanthanoidmetalesterhomoenolate (β-lanthanoid metal substituted ester) is postulated as a reaction intermediate.