Novel Synthesis of (Butatriene)hexacarbonyldiiron Complexes. Stereochemical Aspects and an X-ray Crystal Structure Determination

(Butatriene)hexacarbonyldiiron complexes with various substituents at either end of the triene ligand were prepared in good yields from 2-butyne-1,4-diols and enneacarbonyldiiron. For (2,5-dimethyl-2,3,4-hexatriene)hexacarbonyldiiron an X-ray crystal structure was obtained.