JOURNAL OF HETEROCYCLIC CHEMISTRY, vol.43, no.3, pp.585-591, 2006 (SCI-Expanded)
In this study, a new synthetic route to the total synthesis of (+/-)-20- epidasycarpidone (1b) is described. This route involves acid catalyzed ring closure and the formation of the intermediate 13 in the key step. The relative stereochemistry of 13 has been confirmed by X-ray structure analysis. The tetracyclic intermediate 13 was synthesized through several steps starting from 3. The removal of the protecting group of 13 yielded the lactam 15, which was reduced by Red-A(R) to give 16. The synthesis of (+/-)-20-epidasycarpidone (1b) was finally completed by the oxidation of 16.