Clavulone, synthesis

Pd(OAc)2 to give the cyclohexenone 256. In clavulone synthesis, only the silyl enol ether in 257 reacts with Pd(OAc)2 to give the enone 258 [153]. The dehydrogenation can be carried out with a catalytic amount of Pd(OAc)2 using benzoquinone as the reoxidant. Cyclopentenone (260) is prepared from cyclopentanone (259) by using a supported Pd catalyst under 02 atmosphere [154], The enone 261 is converted to the dienone 263 via the dienol silyl ether 262 [155],... 

Clavulones I and II are members of an unusual family of marine prostanoids from the coral Clavularia viridis which are biosynthesiied by a cationic (i.e. non-radical, non-endoperoxide) pathway. The total synthesis of clavulones I and II was accomplished from cyclopentadiene as SM goal. 

Takemoto, M., Koshida, A., Miyazima. K.. Suzuki. K.. and Achiwa, K., Prostanoids and related compounds. Part 4. Total synthesis of clavulones. Chem. Pharm. Bull., 39, 1106, 1991. 

Nagaoka, H., T. Miyakoshi, and Y. Yamada Total Synthesis of Marine Prostanoids Clavulones. Tetrahedron Lett. 25, 3621 (1984). 

Hashimoto, S., Y. Arai, and N. Hamanaka Synthesis of Clavulones (Claviriden-ones). Tetrahedron Lett. 26, 2679 (1985). 

Hashimoto, S., Arai, Y, and Hamanaka, N. (1985) Synthesis of clavulones (claviridenones). Tetrahedron Lett., 26,2679-2682. 

Shibasaki, M. and Ogawa, Y. (1985) Total synthesis of clavulones. Tetrahedron Lett., 26, 3841-3844. 

Igudii, K., Kaneta, S., Nagaoka. H and Yamada, Y. (1989) Synthesis of clavulone derivatives selective clevage of ester bonds in clavulone. Chem. Lett., 157-160. 

Takeda, K., Nakajima, A., and Yoshii, E. (1997) Synthesis of clavulones (claviridenones) via [3+2] annulation using reaction of (P-(phenyllhio)actyloyl)silane with lithium enolate of alkyl methyl ketone. Synlett, 255—256. 

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