Organometallic complexes in synthesis. Part VI. Some oxidative cyclisations of tricarbonylcyclohexadieneiron complexes

Abstract
Tricarbonylcyclohexadienyliron salts of type (2; R2=+), after reaction successively with a β-diketone or a β-keto-ester and manganese dioxide or lead dioxide, give tricarbonyl-cis-3a,7a-dihydrofuraniron complexes of type (3). Use of deuteriated intermediates indicated that the cyclisation occurs with specific loss of the 6-endo-proton.