Substituent effects in the transannular cyclizations of germacranes. Synthesis of 6-epi-costunolide and five natural steiractinolides
作者:Redouan Azarken、Francisco M. Guerra、F. Javier Moreno-Dorado、Zacarías D. Jorge、Guillermo M. Massanet
DOI:10.1016/j.tet.2008.09.017
日期:2008.11
The occurrence and orientation of substituents in the 10-membered ring characteristic of germacranes is determinant in the stereochemical outcome of the acid-promotedtransannularcyclization of these metabolites. An explanation of the synthesis of eudesmanolides and guaianolides produced by the Umbelliferae family of plants is advanced. The syntheses of the natural products 6-epi-costunolide and five