Reactions of lithium with Dimethylfulvene

Article abstract of DOI:10.1021/jo00324a019

<(Diphenylphosphino)methyl>lithium reacts with dimethylfulvene in ether or THF to yield exclusively lithium isopropenylcyclopentadienide, the product of proton transfer.Neither steric nor electronic effects alone appear sufficient to explain this anomalous result.A similar reaction in petroleum ether gives rise to three major products: lithium <1,1-dimethyl-2-(diphenylphosphino)ethyl>cyclopentadienide and the dilithium salts of 6-(1,3-cyclopentadienyl)-6,8,8-trimethylbicyclo<3.3.0>octa-1,3-diene and 2,4-bis(1,3-cyclopentadienyl)-4-methyl-1-pentene.The latter compound is a new dimethylfulvene dimer whose monoanion had previously been proposed but not observed as an intermediate in the anionic oligomerization of dimethylfulvene.