A putatively unfeasible heck reaction - From cyclopentenones to annulated ring systems

2-Iodocyclopentenones undergo a Heck reaction with allylic and homoallylic alcohols, in acceptable yields, to give dicarbonyl compounds useful for the construction of annulated cyclopentanones. In contrast, the corresponding iodo-substituted cyclohexenones, cycloheptenones and acyclic a,p-unsaturate d ketones are far less or even unsuitable for Heck reactions of this type.