… the synthesis of γ-alkylidenebutenolides via palladium-catalyzed ene-yne coupling and palladium-or silver catalyzed lactonization of (Z)-2-en-4-ynoic acids. synthesis …
The diacetates of rubrolides A, C, D, and E (1 a—d) were prepared in modest yields by the Pd-catalyzed cross coupling-lactonization tandem reaction of 5a or Sh with 6a or 6b using Cl2Pd (PPh3) 2 and CuI as catalysts. The feasibility of converting the diacetates into rubrolides was demonstrated by the synthesis of rubrolide C by treatment of lb with methanolic K 2CO3 in THF. A detailed investigation of various parameters and conditions ...
