Reactions Between 6,6-Dialkylfulvenes and α-Picolinyllithium or α-Pyridyllithium——The Synthesis and Structure of Pyridyl Substituted Cyclopentadiene and Its Derivatives of Iron

<正> Exo-cyclic double-bond addition of 6,6-dialkylfulvene and 6,6-polymethylenefulvene withα-pyridylmethyllithium (α-picolinyllithium) results in substituted cyclopentadienyl lithium,which is hy-drolyzed or reacted with ferrous chloride to give α-picolinyl dialkylmethyl cyclopentadiene or bis[-α-picolinyldialkylmethyl] ferrocene,respectively,α-Pyridyllithium also affords exo-cyclic double-bond addition with 6,6-pentamethylenefulvene but it abstracts α-hydrogen from 6,6-tetramethylenefulvene.Structure of 1,1’-bis[1- (α-picolylinyl)cyclopentyl] ferrocene has been determined by X-ray diffraction.The parent ferrocene in the three independent molecules (Ⅰ,Ⅱ,Ⅲ) are almost eclipsed,of which accordingto the relative orientation of the substituents of the two cyelopentadienyl rings in a molecule,they show twodifferent conformations.Molecules Ⅰ and Ⅱ are considered to be the same and molecule Ⅲ is of their mirrorimage.