When [Fe(CO)5] is refluxed with cyclopentadiene, compound A is formed which has the empirical formula C8H6O3Fe and a complicated 1H-NMR spectrum. Compound A readily loses CO to give compound B with two 1H-NMR resonances, one at negative chemical shift (relative intensity 1) and one at around 5 ppm (relative intensity 5). Subsequent heating of B results in the loss of H2 and the formation of compound C. Compound C has a single 1H-NMR resonance and the empirical formula C7H5O2Fe. Compounds A, B, and C all have 18 valence electrons: identify them and explain the observed spectroscopic data.