Abstract: The Caulilide which shows a potent cytotoxicity was synthesized from 2,6,6trimethylcyclohex2ene1,4dione via selective ketalization, Wittig reaction, deprotection, hydrolysislactonization and reduction in 60% total yield, in which wittig reaction was the key step. The difficulty of this reaction came from the strong blocking effect, many reaction conditions were optimized, a better yield of this reaction was gained in 578%. The synthesis of caulilide was completed by reduction of a lactone with NaBH4, the crude product was separated by high performance liquid chromatography to give the target compound.

Key words: Caulilide, 2,6,6-Trimethylcyclohex-2-ene-1,4-dione, Wittig reaction, Synthesis