GENERAL-SYNTHESIS AND METAL-COMPLEXES OF FUSED-RING BICYCLIC CYCLOPENTADIENES

A simple new synthesis of cyclopentadienes possessing fused hydrocarbon (CH2)n chains is based upon rearrangement of spirolactones. These latter compounds can be made from commercially available oxiranes in a three-step procedure. Cyclopentadienes containing five- and six-membered alkylidene groups, -(CH2)5- and -(CH2)6-, respectively, in 1,2-positions were thus prepared. They were employed as precursors to generate ligands L for novel neodymium and zirconium complexes of the types L2ZrCI2, (L2NdCl)2, and L3Nd. Single-crystal X-ray structures of these complexes are reported.