Enantioselective Total Synthesis of Aspergillide C
作者:Tomohiro Nagasawa、Shigefumi Kuwahara
DOI:10.1021/ol802803x
日期:2009.2.5
The first enantioselective totalsynthesis of aspergillide C, a cytotoxic 14-membered macrolide isolated from the marine-derived fungus Aspergillus ostianus, has been accomplished from a commercially available chiral glycidol derivative by a 12-step sequence involving an expeditious preparation of a cyclic acetal intermediate and a trans-selective Ferrier-type two-carbon homologation reaction.
The first total synthesis of angiolam A has been accomplished in 18 steps. Key steps include vinylogous Mukaiyama aldol reactions of aldehyde-derived dienol ethers, conjugate reduction of the resulting double bond followed by diastereoselective protonation and the Witzeman protocol for macrolactamization. Comparison of the optical rotation of the synthesized material with the isolation data established that the absolute configuration of angiolam A is opposite from the proposed structure.