rubbery polymers made by anionic polymerization can be coupled with tin halides or silicon halides to improve the characteristics of the rubber for use in some applications , such as tire treads . in cases where the rubbery polymer was synthesized utilizing a polar modifier it is difficult to attain a high level of coupling . this invention is based upon the unexpected finding that coupling efficiency can be significantly improved by conducting the coupling reaction in the presence of a lithium salt of a saturated aliphatic alcohol , such as lithium tamylate . this invention discloses a process for coupling a living rubbery polymer that comprises reacting the living rubbery polymer with coupling agent selected from the group consisting of tin halides and silicon halides in the presence of a lithium salt of a saturated aliphatic alcohol . the lithium salt of the saturated aliphatic alcohol can be added immediately prior to the coupling reaction or it can be present throughout the polymerization and coupling process . lithium tamylate reacts with water to form t - amyl alcohol during steam stripping . since t - amyl alcohol forms an azeotrope with hexane , it co - distills with hexane and can contaminate recycle feed streams . this problem of recycle stream contamination can be solved by using metal salts of cyclic alcohols that do not co - distill with hexane or form compounds during steam stripping which co - distill with hexane . thus , the use of metal salts of cyclic alcohols is preferred for this reason and because they are considered to be environmentally safe .