| abstract |
Process for preparing a methylene-bridged cyclopentadienyl compound n The present invention relates to a process for preparing a methylene-bridged biscyclopentadienyl compound having the formula I ##STR1## Where L are, independently of one another, identical or different and are each a cyclopentadienyl group, by reactin one or two cyclopentadienyl compounds LH with formaldehyde in monomeric, oligomeric or polymeric form or formaldehyde-generating reagents in the presence of at least one base and at least one phase transfer catalyst. |