Synthetic studies toward the kempane diterpenes. Approaches to the assembly of the ring system
作者:Guanglin Bao、Chunjian Liu、D. Jean Burnell
DOI:10.1039/b104986k
日期:2001.10.11
The ringsystem of the kempanediterpenes has been assembled from the Diels–Alder adduct 7 by a highly chemo- and stereoselective attack of lithium ethoxyacetylide on its apparently more encumbered carbonyl (to give 11), removal of the silyl protecting group (12 and 13), concomitant deoxygenation and ethoxyethyne solvolysis (18 and 19), reconjugation and epimerization (21), and then a series of reductive