[1-3-η-1-Methoxy-anti-2,3-bis(methoxycarbonyl)-prop-2-en-1-ylidene]tricarbo nyliron (1) reacts with 2,2 -bipyridyl or 1,10-phenanthroline to give corresponding 2-ferracyclopent-4-en-1-one derivatives, 3d and 3e, in 45 and 80% yields respectively. Complex 3d crystallizes in the triclinic space group P1 with a = 13.526(10), b = 15.71(2), c = 11.06(1) 9, α = 91.51(10)°, β = 108.50(6)°, γ = 103.26(7)°, and Z = 4. Complex 3d has octahedral Fe(II) and two carbonyl groups are in cis configuration; the acyl group and one of the bipyridyl nitrogen are in trans configuration.