Organoiron complexes in organic synthesis. Part 13. Synthesis of 6,6-disubstituted tricarbonyl(cyclohexadienylium)iron salts, and their conversion into 4,4-disubstituted cyclohexa-2,5-dienones

Abstract

Oxidative cyclisation of cyclohexadiene–Fe(CO)₃ complexes having a hydroxy-group in the β-position of a 5-exo_Fe- substituent can be effected with either thallium (III) trifluoroacetate or iron(III) chloride on silica gel. The products were readily converted into the title compounds.