| abstract |
A ein Alkalimetall-, Erdalkalimetall- oder Oniumhalogenid ist, B ein organisches Solubilisierungsmittel für die Komponente A ist, C eine Lewis-Säure oder elementares Jod ist, mit der Maßgabe, daß mindestens eine der Komponenten A oder C ein Jodid ist. Process for the preparation of 2,5-dihydrofurans of the general formula I in which the radicals R¹, R², R³, R⁴, R⁵ and R⁶ are the same or different and stand for hydrogen or C₁- to C₄-alkyl groups, by the catalytic rearrangement of 3,4-epoxy-1-butenes of the general formula II by catalyzing the rearrangement by means of a catalyst system comprising components A, B and C at temperatures of 60 to 200 ° C, in which the catalyst component A is an alkali metal, alkaline earth metal or onium halide, B is an organic solubilizing agent for component A, C is a Lewis acid or elemental iodine, with the proviso that at least one of components A or C is an iodide. |