Facile Synthesis of β-Organotellurobutenolides via Electrophilic Tellurolactonization of α-Allenoic Acids.

We report a convenient and highly efficient method for the synthesis β-organotellurobutenolides by the aryltellurenyl halides-induced electrophilic tellurolactonization of α-allenoic acids under mild conditions. The resulting β-organo-tellurobutenolides can be utilized as precursors for versatile butenolide derivatives through a substitution reaction with organocuprate reagent or Pd]Cu(I)-catalyzed cross-coupling with terminal alkyne. [ABSTRACT FROM AUTHOR]