Linked Life Data

19418521

Source:http://linkedlifedata.com/resource/pubmed/id/19418521

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2009-6-4
pubmed:abstractText
Two different approaches to the eleven-membered biaryl ether lactones of the aspercyclide family are disclosed. The core regions of these highly strained targets, which are able to interfere with the binding of immunoglobulin E to its high affinity receptor, can either be forged by ring-closing olefin metathesis (RCM) or by a highly diastereoselective chromium-mediated Nozaki-Hiyama-Kishi (NHK) reaction. Whereas the RCM approach turned out to be responsive to minor changes in the substitution pattern of the substrate, the NHK route is more generally applicable. The preparation of the required cyclization precursor 43 hinged on a palladium-catalyzed ortho-iodination reaction of 2-methylbenzoic acid, an efficient copper-catalyzed Ullmann coupling, and a Takai-Utimoto olefination as the key steps. Moreover, the esterification of the 2,6-disubstituted benzoic acid 34 with the sterically hindered secondary alcohol 37 was far from trivial. However, this and related transformations were accomplished by recourse to the corresponding acid fluorides, which provided excellent yields in cases in which the more commonly used acid chlorides or mixed anhydrides failed to afford any of the desired products.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1521-3765
pubmed:author
pubmed:issnType
Electronic
pubmed:day
8
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5956-68
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Total synthesis of the aspercyclides.
pubmed:affiliation
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't