Various types of mono- and binuclear ferracyclic (η 3 -allyl)iron complexes were prepared from unsaturated diols. Chelated tricarbonylironcarbene complexes 5 and 7 featuring a partially ligated (1,3-η 3 )-pentadienyl ligand were built up from the diene-1,2-diols 4 or 8, respectively. 2-Hexyn-4-ene-1,6-diol (12) reacted with enneacarbonyldiiron to furnish the binuclear 1-lactonyl-(1,3-π:2-σ)-allyldiiron complex 13 under mild conditions. Its structural details are discussed. Similar complexes 17 with five- to seven-membered lactone substituents at the allyl ligand were prepared likewise from the corresponding 2-alkyne-1,n-diols (16).