Application of a Domino Intramolecular Enyne Metathesis/Cross Metathesis Reaction to the Total Synthesis of (+)-8-<i>e</i><i>pi</i>-Xanthatin
作者:David A. Kummer、Jehrod B. Brenneman、Stephen F. Martin
DOI:10.1021/ol051711a
日期:2005.10.1
[reaction: see text] The first total synthesis of the novel sesquiterpene lactone (+)-8-epi-xanthatin (1) has been achieved starting from the commercially available ester 8. The synthesis features an asymmetric aldol reaction and palladium-catalyzed carbonylation/lactonization sequence leading to 4 and a domino ring-closingenynemetathesis/crossmetathesisreaction to afford 1.
The total synthesis and determination of the absolute configuration of (+)- and (-)-sundiversifolide have been achieved via intramolecular acylation and Wittig-lactonization as the key steps. The xanthanolide sesquiterpene lactones, 8-epi-xanthatin (1), dihydroxanthatin (2), and xanthatin (3) were also prepared, starting from a common intermediate derived from the synthesis of sundiversifolide. (C) 2010 Elsevier Ltd. All rights reserved.
AHMED, AHMED A.;JAKUPOVIC, J.;BOHLMANN, F.;REGAILA, H. A.;AHMED, A. M., PHYTOCHEMISTRY, 29,(1990) N, C. 2211-2215
作者:AHMED, AHMED A.、JAKUPOVIC, J.、BOHLMANN, F.、REGAILA, H. A.、AHMED, A. M.
DOI:——
日期:——
Domino intramolecular enyne metathesis/cross metathesis approach to the xanthanolides. Enantioselective synthesis of (+)-8-epi-xanthatin
作者:David A. Kummer、Jehrod B. Brenneman、Stephen F. Martin
DOI:10.1016/j.tet.2006.05.019
日期:2006.12
palladium-catalyzed carbonylation reaction to form acrylate 34. Compound 34 was then subjected to a deprotection/lactonization sequence to furnish enyne 21, which underwent a domino enyne ring-closing metathesis/crossmetathesis process to form a seven-membered carbocycle and (E)-conjugated dienone, thereby completing the synthesis of 1. This domino ruthenium-catalyzedmetathesis reaction thus serves as an efficient
作者:Ahmed A. Ahmed、J. Jakupovic、F. Bohlmann、H.A. Regaila、A.M. Ahmed
DOI:10.1016/0031-9422(90)83040-8
日期:1990.1
in addition to several known sesquiterpenelactones and some other compounds, a lactone with a newcarbonskeleton, two dimeric sesquiterpenelactones, an endoperoxide, an 11,13-dihydroxanthanolide and a further sesquiterpene acid. The structures were elucidated by highfield NMR techniques. The structure of the pentacyclic lactone was confirmed by partial synthesis from 8-epixanthatin.