Abstract The 1, n-diallenyl diketones 8a− j were prepared and subjected to reactions with the [PdCl 2 (MeCN) 2] catalyst. Upon decreasing the length of the bridge between the allenyl ketone units, first we obtained the (E) isomer 10 as the macrocyclic product and then the (Z) isomer 11 accompanied by the exocyclic double bond isomer 12. In all cases, the open- chained 1, n-difuryl alkanes were isolated as side-products. The analogous preparation ...