Abstract: The total synthesis of(±)caulilide(1) which shows a potent cytotoxicity is described.Cyclocitral(2) was prepared from citral via citralylimine in 85%～90% yield.The reaction of 2 with KCNfollowed by dehydration afforded nitrile 3 in 56% yield.Allyl oxidation of 3 was performed by using pyridium dichromate-t-butyl-hydroperoxide to give ketonitrile(4) which was a mixture of geometrie isomers of 4a(cis) and 4b(trans).After separation on a silica gel column, the cis isomer 4a was then hydrolyzed and simultaneously lactonized in conc.HCl solution to form a lactone(±)-5.The synthesis of caulilide(1) was completed by the reduction of 5 with NaBH₄. The crude product was separated by high performed chromatography to give the target compound (±)-1.

Key words: Caulilide, Total synthesis, Homo-monoterpene lactone, Citral