作者:Rakeshwar B. Chhor、Bernd Nosse、Sebastian Sörgel、Claudius Böhm、Michael Seitz、Oliver Reiser
DOI:10.1002/chem.200390019
日期:2003.1.3
development of a new method for the enantioselective synthesis of disubstituted gamma-butyrolactones is reported. Based on this strategy, the totalsynthesis of three paraconic acids, that is (-)-roccellaricacid, (-)-nephrosteranicacid and (-)-protopraesorediosic acid, and the formal totalsynthesis of (-)-methylenolactocin and (-)-protolichesterinic acid is described, which are important because of their
A strategy towards the stereoselectivesynthesis of bi-and tricyclic sesquiterpene lactones is reported. As key step radical cyclizations of appropriately functionalized trans-4,5-disubstituted γ-butyrolactones, which arereadily available from methyl 2-furoate, were carried out to give rise to 5,6-, 5,7- and 5,7,5-ring systems in diastereo- and enantiomerically pure form.
Stereoselective routes to aryl substituted γ-butyrolactones and their application towards the synthesis of highly oxidised furanocembranoids
作者:Allan Patrick G. Macabeo、Andreas Kreuzer、Oliver Reiser
DOI:10.1039/c1ob05113j
日期:——
Titanium chelate addition of aryl nucleophiles to cyclopropyl aldehyde 6 followed by a tin-catalyzed one-pot retro-aldol, acetalisation and lactonisation sequence afforded cis and trans γ-aryllactone acetals. A γ-furyllactone derived by this approach was further transformed in two steps to model compounds for the oxidised northeastern sectors of selected Pseudopterogorgia diterpenoids.
their biological evaluation is reported, featuring a new strategy for the asymmetricconstruction of γ-butyrolactones with stereogenic side chains in the 4-position. Starting from the renewable resource methyl 2-furoate, the sesquiterpene lactone was synthesized in 9 steps and 4.8% overall yield via an asymmetriccyclopropanation and two diastereoselective nucleophile additions making use of a donor-
Facile Asymmetric Synthesis of the Core Nuclei of Xanthanolides, Guaianolides, and Eudesmanolides
作者:Bernd Nosse、Rakeshwar B. Chhor、Won Boo Jeong、Claudius Böhm、Oliver Reiser
DOI:10.1021/ol034141s
日期:2003.3.1
Bicylic and tricyclic gamma-butyrolactones with 5,7-, 5,6,5-, 5,6,6-, or 5,7,5-fused ring systems, being found in xanthanolides, eudesmanolides, and guaianolides, were readily synthesized from methyl furan-2-carboxylic acid. Key steps were a copper(I)-catalyzed asymmetric cyclopropanation, Sakurai allylations, intramolecular ene reactions, and ring-closing metathesis reactions.