 1,2 and 3,4 dominant polyisoprene is produced MoO2Cl2 catalyst supported by phosphorus ligand and Al(OPhCH3)(i-Bu)2 co-catalyst.Natural Gutta-percha and synthesized trans-1,4-polyisoprenes are used for golf balls.Natural rubber and synthesized cis-1,4-polyisoprene are used for elastomer.