Journal of the Brazilian Chemical Society
On-line version ISSN 1678-4790
ALVES, José C. F. and FANTINI, Edna C.. Chemical transformations of eremanthine: synthesis of micheliolide and 1(R),10(R)-dihydromicheliolide. J. Braz. Chem. Soc. [online]. 2005, vol.16, n.4, pp. 749-755. ISSN 1678-4790. http://dx.doi.org/10.1590/S0103-50532005000500012.
Eremanthine (1), an abundant natural substance, was transformed in four steps into diol 5. Hydrogenolysis of 5 (55 psi of H2, Pd/C, 30 min) furnished 7. Hydrogenation of 5 using a low hydrogen pressure (5 psi) and a short reaction time (15 min) led to a mixture of 6 and 7 (3:1). Compounds 6 and 7 were then transformed respectively to the a-methylene-g-lactones micheliolide (9) and 1(R),10(R)-dihydromicheliolide (8), after elimination of methanol.
Keywords : anticancer sesquiterpene lactones; eremanthine; micheliolide.