| Abstract |
Double 3-oxocyclopentenylation of the fulvalene dianion, followed by metalation, results in the four isomeric bis(enones) 1 which were elaborated via the bis(cyclopentadienes) 2 to the four regio- and stereoisomeric forms of(quatercyclopentadienyl)tetratungsten (connectivity 1,1 ,2 ,1 ,3 , 1 (3a,b and 4a,b) and 1,1 ,3 ,1 ,3 ,1 (3c,d and 4c,d)). The molecular structures of la and Ib have been determined by X-ray analysis. The tetramethyl complex 5 is obtained from 2d by a metalation-methylation sequence involving deprotonation of the intermediate bis(tungsten hydride) with K+((OC)-O—(CH3)(3)). |
