Enol Tosylate for Stereoretentive Cross Coupling Reactions

Methyl (Z)-3-(p-toluenesulfonyloxy)but-2-enoate (1) is a useful building block featuring an enol tosylate moiety which can be utilized in stereoselective cross coupling reactions. In this instance, treatment of 1 under either Negishi or Sonogoshira conditions affords two coupled products substituted at the tosyl position.¹⁾ This reaction has the advantage of stereoretentively proceeding of alkene moiety. Furthermore, total synthesis of insect juvenile hormones from 1 has been reported.²⁾