M. Sellin et al., CHAIN-RING ISOMERISM VS CARBON-CARBON COUPLING ON 2 (TETRACARBONYLIRON)-GAMMA-KETOESTERS - CIS-[FE(COR)(COCOR')(CO)(4)] (R=ME, R'=OME R=OME, R'=ME), Chemical communications, (7), 1996, pp. 857-858
Ferra-gamma-ketoesters 1 and 2 induce thermally either a carbon-carbon
coupling process or a chain-ring isomerization; the orientation of th
e reaction likely depends on the proximity of the ester group to the m
etal centre.