92481-63-5Relevant articles and documents
Synthetic Studies on Terpene Compounds. Part 13. Total Synthesis of Fraxinellone
Tokoroyama, Takashi,Fukuyama, Yoshiyasu,Kubota, Takashi,Yokotani, Kenji
, p. 1557 - 1562 (2007/10/02)
The total synthesis of fraxinellone (1), the simplest example of degraded limonoid, via the 6-formyl-2,6-dimethylcyclohex-2-enecarboxylates (2) is described.In the initial approach the C-6 methylation of ethyl 6-formyl-2-methylcyclohex-2-enecarboxylate (7) was carried out by cyclopropanation and ring cleavage which unexpectedly gave the bicycloheptane compound (20), with a poor yield of the desired product.Subsequently, the key intermediate (2) was synthesized effectively by the Diels-Alder reaction between ethyl 3-methylpenta-2,4-dienoate and methacrolein.The reaction of the aldehyde ester (2) with furyl-lithium followed by double-bond isomerization with base afforded (+/-)-fraxinellone, together with the corresponding diastereoisomer.
