Etude de la structure des oligomeres de l'isoprene desactives par les halogenures d'alcoyle

The deactivation of oligoisoprenyllithium RM_n^?, Li⁺ by an alkyl halide R′X yields two kinds of products: RM_nR′ and RM_nR; the microstructure of the isoprenic units in the oligomer is mainly 4,1 and 4,3 and it is determined by the addition to the active chain of an isoprene molecule or of the alkyl halide molecule. The microstructures of RM_nR′ and of RM_nR are different. The results indicate two kinds of halogen-lithium reactions leading to the products RM_nR: between the excess of initiator RLi and the alkyl halide or between oligoisoprenyllithium and the alkyl halide.